Will 77 grain bullets stabilize in a 1:9 twist barrel?

Some of you have been following my published results with the 12 FV .223 on the “Ammunition & Reloading” forum in the “First results with new 12 FV .223” with the factory plastic stock and on the “110-Series Bolt Action Rifles” forum with the Oryx chassis in the “Documented results from replacing the 12 FV factory stock with an Oryx Chassis” thread.

While I was reporting the results on both threads, I got a note from another shooter who told me that he shot 77 gr SMKs in his 1:9 twist .223 and had good results.
He claimed that the bullet shape overcame the stabilization problem.

I have had great results with 77 grain SMKs and TMKs in my 1:8 twist Les Baer .223 but I have always read that a 1:9 twist wouldn't stabilize bullets over 73 gr bullets, so I never tried them in my two 1:9 twist rifles. In fact, both Sierra 77 grain bullets have a warning not to use the 77 grain bullets in barrels with twist slower than 1:8.

Always curious to try something I haven’t tried yet, I disregarded the long-held belief that a 1:9 twist can’t stabilize 77-grain bullets, and experimented with 77-grain Sierra SMK and TMK bullets in my Savage 12 FV 1:9 twist barrel. Surprisingly, the 77 grain bullets have been consistently more accurate than even the 69 grain bullets that the 12 FV really shot well.

Here is a summary of the results of 5 round groups sorted by bullet weight and by average.
By Weight By Average
Wgt. Avg. Median St Dev # Grps. Rank ----Wgt. Avg. Median St Dev # Grps. Rank
50 0.390 0.392 0.064 --- 3------ 6 ------- 77 0.285 0.271 - 0.066 - 94 ----- 1
52 0.366 0.382 0.079 --- 11 ---- 4 ------- 69 0.313 0.286 - 0.083 - 39 ----- 2
53 0.376 0.366 0.082 --- 8 ------ 5 ------ 55 0.343 0.305 - 0.094 -- 4 ------ 3
55 0.343 0.305 0.094 --- 4 ------ 3 ------ 52 0.366 0.382 - 0.079 - 11------ 4
60 0.487 0.487 ------- --- 1 ------ 7 ----- 53 0.376 0.366 - 0.082 -- 8 ------ 5
68 0.653 0.653 0.001 --- 2 ------ 9 ----- 50 0.390 0.392 - 0.064 -- 3 ------ 6
69 0.313 0.286 0.083 --- 39 ----- 2 ------ 60 0.487 0.487 - --------- 1 ------ 7
70 0.619 0.670 0.189 --- 4 ------ 8 -------70 0.619 0.670 - 0.189 -- 4 ------ 8
77 0.285 0.271 0.066 --- 94 ----- 1 ------ 68 0.653 0.653 - 0.001 -- 2 ------ 9
All 0.319 0.288 0.102 --166 ---------------All 0.319 0.288 - 0.102 -166

Note: I tend to shoot bullets that shoot the most accurately, but I have only been shooting the 77 grain bullets since June 19^th, so I have really been impressed by the accuracy the 77 grain bullets produce and the group counts show it.
The difference in performance in the 69 and 77 grain bullets needs to be explored in a number of ways since both bullet weights were shot in two different stocks and with two different primers.

I had been shooting CCI BR-4 primers with Lapua brass (made to use small rifle primers) and after a member reported that he was having problems with loose primer pockets with Remington 7 ½ BR primers I offered to try those primers because I had over 5,000 lying around. I tried the Remington 7 ½ BR primers and found that they performed slightly better than the CCI BR-4s so I shot more loads using them to see if the results would hold up with a larger statistical sample. I also reported that they were slightly smaller in diameter and were easier to fit in to the primer pockets in Lapua brass that had been reloaded more than 11 times, but weren’t especially loose. The results showed that Remington primers were performing well.

Just a few weeks after trying the Remington primers, I purchased an Oryx stock for the 12 FV .223 to get a detachable magazine. That added another potential variation in the results so I analyzed the data to see if the results were consistent under both the primer change and the plastic factory stock to aluminum chassis change.

Comparison of 12 FV .223 Factory Stock with Oryx Chassis
------------------------------------------ Savage Factory Plastic ------------ Oryx Chassis
------------------- Bullets ----------------- Avg. Median St Dev # Grps. --- Avg. Median St Dev # Grps. Delta %Impr
Sierra Match King # 1380 - 69 gr -------0.329 0.303 0.087 --- 10 ------ 0.307 0.295 0.098 ---- 7 ---- 0.022 6.7%
Sierra Tipped Match King #7169 - 69 gr 0.304 0.288 0.061 --- 12 ------ 0.258 0.272 0.038 ---- 7 ---- 0.046 15.2%
Sierra Match King # 9377 - 77 gr ------ 0.344 0.327 0.118 --- 11 ------- 0.250 0.245 0.016 --- 11 ---- 0.094 27.3%
Sierra Tipped Match King #7177 -77 gr 0.272 0.266 0.039 --- 20 ------- 0.286 0.286 0.059 --- 51 ---- 0.014 -5.0%
----------------------Overall ---------- 0.296 0.282 0.078 --- 53 ------- 0.280 0.272 0.059 --- 76 ---- 0.016 5.4%

The Oryx chassis provided some improvement but it wasn’t as consistent as I would have expected. The biggest improvement came with the 77 SMK bullets and the 77 TMK bullets actually performed better in the factory stock. That was a surprise and there is no apparent reason for the difference that I can determine.

Comparison of 12 FV .223 with CCI BR-4 versus Remington 7 1/2 Primers - equivalent Jump
------------------------------------------ CCI BR-4 primers ----------Remington 7 1/2 BR Primers
----------------------Bullets--------------- Avg. Median St Dev # Grps. Avg. Median St Dev # Grps. Delta %Impr
Sierra Match King # 1380 - 69 gr ------- 0.399 0.422 0.078 --- 3 --- 0.303 0.287 0.084 -- 14 ---- 0.096 24.2%
Sierra Tipped Match King #7169 - 69 gr- 0.354 0.339 0.065 --- 5 --- 0.264 0.272 0.030 -- 14 --- 0.090 25.5%
Sierra Match King # 9377 - 77 gr ------- 0.352 0.287 0.140 --- 8 ---- 0.265 0.250 0.038 -- 15 --- 0.087 24.7%
Sierra Tipped Match King #7177 -77 gr 0.269 0.282 0.051 -- 24 ---- 0.289 0.277 0.055 -- 47---- 0.020 -7.4%
-------------------------Overall -------- 0.306 0.291 0.090 -- 40 ---- 0.283 0.272 0.056 -- 90 --- 0.023 7.4%

The performance with the different primers shows just about the same kind of results, even down to the better performance for the CCI primers over the Remington primers for the 77 TMK bullets when all the other bullets performed better with the Remington primers. Again, there doesn’t seem to be an apparent reason for the difference that I can determine from looking at the data.

Confirmation using other 1:9 twist rifles
I then asked two range buddies who had 1:9 twist .223 bolt actions to test how their rifles shot with 77 grain bullets.
Two tried 77 gr Federal Gold Medal Match with SMK bullets in their rifles.
One shot a 12 FV .223 and the other shot a CZ 527 Varmint .223, both with 1:9 twists.

The Savage 12 FV shot factory Federal Premium Gold Medal Match SMK 77 gr ammo to a 16.1% larger average than his factory average for all bullet weights.
The same 12 FV shot factory Nosler Custom Competition 77 gr ammo to a 15.6% smaller average than his factory average for all bullet weights.

At a later session, the Savage 12 FV owner tried hand loads using 77 TMK bullets and shot the hand loads to a 11.2% smaller average than his hand load average for all bullet weights.
The 77 grain TMK hand load average was 40.3% smaller than the 77-grain factory SMK average and 28.0% smaller than the Nosler CC average.
The 77 grain TMK hand load average was also 9.6% smaller than the rifle’s 69-grain SMK hand load average.

The owner of the CZ 527 shot factory Federal Premium Gold Medal Match SMK 77 gr ammo to a 13.2% smaller than his factory ammo average for all bullet weights.

Conclusion:

The historical concerns that a 1:9 twist barrel will not stabilize a 77-grain bullet appears to be a myth, at least for Sierra SMK and TMK bullets and Nosler Custom Competition bullets, even though both the Sierra boxes and Nosler CC boxes clearly advised that their bullets were only recommended for 1:8 twist barrels or faster.

Next time I head out to the 800 yard range I will take my 9 twist .223 and try some 77 TMK's at distance. I was stopping at 69 thinking it would be a waste going heavier...

Gosh, celltech, that was a quick response.
You must have read my mind as I was typing the post.

I also was convinced that 69s were about the limit when the 70s didn't perform well.

I am so pleased with the performance of the 77 SMKs and 77 TMKs that I just bought another 500 of each.
I am loading for the 12 FV and my CZ 527 Varmint this evening for a Friday morning session.

Good luck at 800 yards with your 77 TMKs.
Load them out for a 0.020 jump so they can really shine.

it is all about LENGTH, not weight.
9 will stabilize some not all
plastic tips can cause issues,( hornady 75 match vs 75 amax)
all guns are different, change altitude, temp, humidity.
bbl lenght limits velocity.
problems show up quicker in shorter bbls

One of the things that surprised me is that CFJunkie is nearer to sea level (and high humidity) and I am closer to 5000ft elevation (and low humidity) and we both see better groups with the 77gn bullets.

Sierra specifically states that their bullets should be used with faster twist barrels. 1:10 or faster for 69gn and 1:8 or faster for 77gn. I am assuming that Sierra is playing it a bit safe in case someone wanders out of the 'envelope', such as a high air density environment and marginal velocity.

FWIW, the 75gn Hornady ELD's also work with my 1/9 twist barrel, but, I have not tried them at 600yds, only 400yds.

PS it is not all about length. That refers to the simplified formulas for stability that assume a football shaped bullet at Mach 2.5. For actual calculations you need bullet shape details, as well as mass, to calculate things like polar and transverse moments.

The only reason I started playing with the 77gn smk mk262 mod 1 was because of the bulk supply I could get my hands on.
I read and read on they wouldn’t work.
My seal buddy said shut up and spend some time on the range with them.
My rifle is a 2007-9 predator 10.
A truck gun it was. Barrel rode on the floor board and very rarely cleaned.
Basic 3x9-40 leupold scope.

It shot that load with no mods to the rifle at 1.5 or so MOA.
That wasn’t good enough for me as it would shoot the little blitz king into tiny groups.
I almost gave up on the 77gn smk.

So I kept reading and wanted to improve the rifle. I should have used process of elimination before changing things to see what worked and what didn’t.
All at once I bedded the plastic stock and stiffened it up and shaved forearm away from the barrel. A lot.
Cut the barrel an inch and recrowned it.
Disclaimer I took the gun to a smith to evaluate the gun and give advice.
He said there is heavy pitting at the crown lets cut a new one and there was light pitting down the tube the whole way. Again a truck gun. After the new crown he scrubbed the bore clean clean.
Torqued the action to my backyard shop bedding job to 65# in the front and 25# in the back. He’s a long range bench guy.
I put a fixed 12x swfa scope on it. The recital has that little dot in the cross hair. So.. now I can hold inside a 1” dot at 100yds. The basic Leupold the reticle almost covered the dot..

Any way back to the range 100yd range at the time. After about 10 fowl shots I started to shoot some groups. Well dang on. Back to the tiny groups I expect with a .223

What made the difference? I don’t know.

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This is my verified dope to 600yds. 3-5” groups pretty consistent.

Cheers all. You all are a wealth of knowledge.


Sent from my iPhone using Tapatalk

Stability is a product of twist AND velocity. Low on velocity? Add more twist. Low on twist? Add more velocity. It is not lost on me that I distilled that down to the simplest variables and that other things like atmospherics play a role as well. Readily available calculators like this one: https://bergerbullets.com/twist-rate-calculator/ are available online.

The bold red text on the end of the box tells you something. And the Sierra reloading manual tells you what twist rate the .223/5.56 bullets will stabilize at.

https://www.wholesalehunter.com/nima...61206_Pic2.jpg

That's nothing more than their bottom line disclaimer.....better to err on the side of caution. When you're on the fence, it better to go faster instead of slower. I've got 90 gr match kings to stabilize with a 1-8" twist, not the 1- 6.5" you absolutely have to have they claim.

Quote:

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Originally Posted by bigedp51

The bold red text on the end of the box tells you something. And the Sierra reloading manual tells you what twist rate the .223/5.56 bullets will stabilize at.

https://www.wholesalehunter.com/nima...61206_Pic2.jpg

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That is why it took me two years before I decided to try them. I stuck with 69gn because I believed Sierra. I am glad I tried the 77's as they shoot so well with my 1/9 twist.

I do believe they put that disclaimer on there simply because of all the slower twist AR's out there with shorter barrels.

at the 600-1000 yards they were intended for ?
i own a very nice krieger 1/7 that was used to test 90's.
27" long and did not work with 90's.
the good news is i got the "used" bbl for all of 75 delivered!

Quote:

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Originally Posted by sharpshooter

That's nothing more than their bottom line disclaimer.....better to err on the side of caution. When you're on the fence, it better to go faster instead of slower. I've got 90 gr match kings to stabilize with a 1-8" twist, not the 1- 6.5" you absolutely have to have they claim.

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The barrels that don't shoot them are probably a true 1-9 twist. The ones that do shoot them are probably a little faster twist. On button rifled barrels you will always get a little drift on the true twist. Very few makers can actually keep the stated twist on button rifled barrels. That is why most use a cut rifled barrel because the twist stated is what it says it is.

I agree that machining has a built in error factor. The question is whether it could be large enough to make a 'marginally stable' bullet stable.
I have no doubt that it is difficult to get an exact twist on barrel rifling, but I doubt if a 1:9 twist turning is going to be off by another 1/2 inch or more out of 9 inches.
I wouldn’t argue that the error could be 2.5% (or less than ¼ inch out of 9 inches) but I would think that more than that would be a major screw up in setting up the rifling lathe.
Maybe Dave or some qualified machinist could give us some idea of how much error would be the norm.

Just to see if the premise that the barrel twist was cut faster than specified, I did the twist test with a cleaning rod and the barrel was very, very close to 1 twist in 9 inches. It wasn't off by anything close to 1/2 inch.

So I went back to the Berger calculator that I had used before but abandoned because all my best shooting bullets were being classified as 'marginally stable'. Somehow I just didn't believe that.

I entered the temperature, velocity and altitude that I was shooting at, and the BC and bullet length of the 77 gr SMK and 77 gr TMK bullets gave the following results:
77 SMK -- bullet stability rating = 1.36 – twist to stabilize = 8.50. Rated as 'Marginally Stable'.
No way a “little faster twist” is going to be ½ inch faster (5%). That lathe would have to really be humming to be that far off.
77 TMK – bullet stability rating = 1.12 – twist to stabilize = 7.75. Rated as 'Marginally Stable'.
That ‘little faster twist’ would have to be a 'whole lot faster' by 1.25 inches or almost 14 %. A 1:8 twist would only be 11.1% faster than a 1:9 twist.


To test the sensitivity of the stability calculator to altitude, temperature and velocity for the 77 gr TMK bullets:
I changed altitude from 250 feet to 2500 ft (900% change) and stability rating changed from 1.12 to 1.22. (0.010 or 8.9%) That is 1% for each 250 feet in altitude.
I changed temperature from 70 to 100 degrees (42.5%) and stability rating changed from 1.12 to 1.18. (0.06 or 5.3%). That is 1% for every 7.5 degrees of temperature change.
I changed velocity from 2540 fps to 2700 fps close to Pmax (6.2%) and stability rating changed from 1.12 to 1.14 (0.02 or 1.7% change). That’s 1% for every 100 fps.
None of those rates of change are incredible and could account for the accuracy that these bullets are showing.

I then tried to determine the effect of bullet length or BC changes on the stability rating:
Then I adjusted only the length of the bullet from 1.069 for the 77 gr TMK to the same length as the 77 gr SMK (1.000) and the stability rating as the 77 SMK changed to the stability rating of the 77 SMK 1.36.
I then adjusted only the BC of the bullet from the 0.420 of the 77 gr TMK to the same BC as the 77 gr SMK (0.372) and the stability rating didn’t change at all.
The Berger Calculator makes Length the only really significant driver in the stability calculation - but contrary to general belief that long thin high BC bullets are better – the calculator says that shorter is better and according to the calculator, BC makes no difference.

Somehow, to me, that is counterintuitive, especially since all my long, high BC bullets shoot more accurately than the stubby low BC bullets, regardless of caliber.
How can the more accurate bullets be less stable?

That is because the simplified equations do not really take into account bullet shape. They assume the bullet is shaped like a football. Aerodynamically that is a bad assumption, especially for supersonic bullets that are designed to have shock waves at specific locations relative to the moments of inertia and the center of gravity. The nose length/ogives and boat tail location, angles and lengths are VERY critical to the bullet performance.

The equations are good for basic questions, but, are NOT good if you are looking at the edges of performance envelopes. As an example, with my front stuffer shooting 550gn paper patch bullets the simplified calculators say they should be stable when they are not. Those bullets have no boat tail so the CG is further back than a football shape.

Good work CF,
I don’t have a chronograph but to get my dope chart correct online I have to plug in close to 2800fps. Then when I go back to the Berger page and punch in the high velocity. I get way closer to stable. I wonder what CB said about they assume bullet shape. I wonder if they are calculating bergers shape, the shape of a football, or? I’m not sure. I wonder if a 90gn bullet made with a heavier material in the same shape and size as serria 69-77gn match bullet would shoot?
As I don’t have two to compare what are the dimensions of he 69 vs 77gn smk? Or bergers 75gn bullet vs serrias 77gn.

Environmental factors are super hard to predict much less calculate besides wind and that’s challenging enough. Snipers use a spotter. I’m at 400ft in the thickest air in the US. Maybe not but downeast NC in the summer is a wall of humidity. The thickness of the mosquitos should be calculated to bullet travel. [emoji23]

Again I wonder what CF and CBs velocity is.


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Quote:

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Originally Posted by mikeinco

at the 600-1000 yards they were intended for ?
i own a very nice krieger 1/7 that was used to test 90's.
27" long and did not work with 90's.
the good news is i got the "used" bbl for all of 75 delivered!

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I think what Fred failed to note there is that he's pushing them at much higher velocities than can be had from a .223. Think 22-250AI, 22-243, 22 BR, 22 Dasher, 22-284 Super Hotrod, etc. With the higher velocity offered by these cartridges you can easily get by with the 1-8" twist.

For all intensive purposes, if you can't push the 90's faster than 3100fps you're better off shooting the 80's.

what is your results at 600 yards ?
as competition bullets, it is where they would be shot.

Quote:

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Originally Posted by CFJunkie

Some of you have been following my published results with the 12 FV .223 on the “Ammunition & Reloading” forum in the “First results with new 12 FV .223” with the factory plastic stock and on the “110-Series Bolt Action Rifles” forum with the Oryx chassis in the “Documented results from replacing the 12 FV factory stock with an Oryx Chassis” thread.

While I was reporting the results on both threads, I got a note from another shooter who told me that he shot 77 gr SMKs in his 1:9 twist .223 and had good results.
He claimed that the bullet shape overcame the stabilization problem.

I have had great results with 77 grain SMKs and TMKs in my 1:8 twist Les Baer .223 but I have always read that a 1:9 twist wouldn't stabilize bullets over 73 gr bullets, so I never tried them in my two 1:9 twist rifles. In fact, both Sierra 77 grain bullets have a warning not to use the 77 grain bullets in barrels with twist slower than 1:8.

Always curious to try something I haven’t tried yet, I disregarded the long-held belief that a 1:9 twist can’t stabilize 77-grain bullets, and experimented with 77-grain Sierra SMK and TMK bullets in my Savage 12 FV 1:9 twist barrel. Surprisingly, the 77 grain bullets have been consistently more accurate than even the 69 grain bullets that the 12 FV really shot well.

Here is a summary of the results of 5 round groups sorted by bullet weight and by average.
By Weight By Average
Wgt. Avg. Median St Dev # Grps. Rank ----Wgt. Avg. Median St Dev # Grps. Rank
50 0.390 0.392 0.064 --- 3------ 6 ------- 77 0.285 0.271 - 0.066 - 94 ----- 1
52 0.366 0.382 0.079 --- 11 ---- 4 ------- 69 0.313 0.286 - 0.083 - 39 ----- 2
53 0.376 0.366 0.082 --- 8 ------ 5 ------ 55 0.343 0.305 - 0.094 -- 4 ------ 3
55 0.343 0.305 0.094 --- 4 ------ 3 ------ 52 0.366 0.382 - 0.079 - 11------ 4
60 0.487 0.487 ------- --- 1 ------ 7 ----- 53 0.376 0.366 - 0.082 -- 8 ------ 5
68 0.653 0.653 0.001 --- 2 ------ 9 ----- 50 0.390 0.392 - 0.064 -- 3 ------ 6
69 0.313 0.286 0.083 --- 39 ----- 2 ------ 60 0.487 0.487 - --------- 1 ------ 7
70 0.619 0.670 0.189 --- 4 ------ 8 -------70 0.619 0.670 - 0.189 -- 4 ------ 8
77 0.285 0.271 0.066 --- 94 ----- 1 ------ 68 0.653 0.653 - 0.001 -- 2 ------ 9
All 0.319 0.288 0.102 --166 ---------------All 0.319 0.288 - 0.102 -166

Note: I tend to shoot bullets that shoot the most accurately, but I have only been shooting the 77 grain bullets since June 19^th, so I have really been impressed by the accuracy the 77 grain bullets produce and the group counts show it.
The difference in performance in the 69 and 77 grain bullets needs to be explored in a number of ways since both bullet weights were shot in two different stocks and with two different primers.

I had been shooting CCI BR-4 primers with Lapua brass (made to use small rifle primers) and after a member reported that he was having problems with loose primer pockets with Remington 7 ½ BR primers I offered to try those primers because I had over 5,000 lying around. I tried the Remington 7 ½ BR primers and found that they performed slightly better than the CCI BR-4s so I shot more loads using them to see if the results would hold up with a larger statistical sample. I also reported that they were slightly smaller in diameter and were easier to fit in to the primer pockets in Lapua brass that had been reloaded more than 11 times, but weren’t especially loose. The results showed that Remington primers were performing well.

Just a few weeks after trying the Remington primers, I purchased an Oryx stock for the 12 FV .223 to get a detachable magazine. That added another potential variation in the results so I analyzed the data to see if the results were consistent under both the primer change and the plastic factory stock to aluminum chassis change.

Comparison of 12 FV .223 Factory Stock with Oryx Chassis
------------------------------------------ Savage Factory Plastic ------------ Oryx Chassis
------------------- Bullets ----------------- Avg. Median St Dev # Grps. --- Avg. Median St Dev # Grps. Delta %Impr
Sierra Match King # 1380 - 69 gr -------0.329 0.303 0.087 --- 10 ------ 0.307 0.295 0.098 ---- 7 ---- 0.022 6.7%
Sierra Tipped Match King #7169 - 69 gr 0.304 0.288 0.061 --- 12 ------ 0.258 0.272 0.038 ---- 7 ---- 0.046 15.2%
Sierra Match King # 9377 - 77 gr ------ 0.344 0.327 0.118 --- 11 ------- 0.250 0.245 0.016 --- 11 ---- 0.094 27.3%
Sierra Tipped Match King #7177 -77 gr 0.272 0.266 0.039 --- 20 ------- 0.286 0.286 0.059 --- 51 ---- 0.014 -5.0%
----------------------Overall ---------- 0.296 0.282 0.078 --- 53 ------- 0.280 0.272 0.059 --- 76 ---- 0.016 5.4%

The Oryx chassis provided some improvement but it wasn’t as consistent as I would have expected. The biggest improvement came with the 77 SMK bullets and the 77 TMK bullets actually performed better in the factory stock. That was a surprise and there is no apparent reason for the difference that I can determine.

Comparison of 12 FV .223 with CCI BR-4 versus Remington 7 1/2 Primers - equivalent Jump
------------------------------------------ CCI BR-4 primers ----------Remington 7 1/2 BR Primers
----------------------Bullets--------------- Avg. Median St Dev # Grps. Avg. Median St Dev # Grps. Delta %Impr
Sierra Match King # 1380 - 69 gr ------- 0.399 0.422 0.078 --- 3 --- 0.303 0.287 0.084 -- 14 ---- 0.096 24.2%
Sierra Tipped Match King #7169 - 69 gr- 0.354 0.339 0.065 --- 5 --- 0.264 0.272 0.030 -- 14 --- 0.090 25.5%
Sierra Match King # 9377 - 77 gr ------- 0.352 0.287 0.140 --- 8 ---- 0.265 0.250 0.038 -- 15 --- 0.087 24.7%
Sierra Tipped Match King #7177 -77 gr 0.269 0.282 0.051 -- 24 ---- 0.289 0.277 0.055 -- 47---- 0.020 -7.4%
-------------------------Overall -------- 0.306 0.291 0.090 -- 40 ---- 0.283 0.272 0.056 -- 90 --- 0.023 7.4%

The performance with the different primers shows just about the same kind of results, even down to the better performance for the CCI primers over the Remington primers for the 77 TMK bullets when all the other bullets performed better with the Remington primers. Again, there doesn’t seem to be an apparent reason for the difference that I can determine from looking at the data.

Confirmation using other 1:9 twist rifles
I then asked two range buddies who had 1:9 twist .223 bolt actions to test how their rifles shot with 77 grain bullets.
Two tried 77 gr Federal Gold Medal Match with SMK bullets in their rifles.
One shot a 12 FV .223 and the other shot a CZ 527 Varmint .223, both with 1:9 twists.

The Savage 12 FV shot factory Federal Premium Gold Medal Match SMK 77 gr ammo to a 16.1% larger average than his factory average for all bullet weights.
The same 12 FV shot factory Nosler Custom Competition 77 gr ammo to a 15.6% smaller average than his factory average for all bullet weights.

At a later session, the Savage 12 FV owner tried hand loads using 77 TMK bullets and shot the hand loads to a 11.2% smaller average than his hand load average for all bullet weights.
The 77 grain TMK hand load average was 40.3% smaller than the 77-grain factory SMK average and 28.0% smaller than the Nosler CC average.
The 77 grain TMK hand load average was also 9.6% smaller than the rifle’s 69-grain SMK hand load average.

The owner of the CZ 527 shot factory Federal Premium Gold Medal Match SMK 77 gr ammo to a 13.2% smaller than his factory ammo average for all bullet weights.

Conclusion:

The historical concerns that a 1:9 twist barrel will not stabilize a 77-grain bullet appears to be a myth, at least for Sierra SMK and TMK bullets and Nosler Custom Competition bullets, even though both the Sierra boxes and Nosler CC boxes clearly advised that their bullets were only recommended for 1:8 twist barrels or faster.

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Quote:

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Originally Posted by hamiltonkiler

Good work CF,
I don’t have a chronograph but to get my dope chart correct online I have to plug in close to 2800fps. Then when I go back to the Berger page and punch in the high velocity. I get way closer to stable. I wonder what CB said about they assume bullet shape. I wonder if they are calculating bergers shape, the shape of a football, or? I’m not sure. I wonder if a 90gn bullet made with a heavier material in the same shape and size as serria 69-77gn match bullet would shoot?
As I don’t have two to compare what are the dimensions of he 69 vs 77gn smk? Or bergers 75gn bullet vs serrias 77gn.

Environmental factors are super hard to predict much less calculate besides wind and that’s challenging enough. Snipers use a spotter. I’m at 400ft in the thickest air in the US. Maybe not but downeast NC in the summer is a wall of humidity. The thickness of the mosquitos should be calculated to bullet travel. [emoji23]

Again I wonder what CF and CBs velocity is.


Sent from my iPhone using Tapatalk

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I do not measure velocity since I got rid of my chronograph years ago. Based on Sierra's tables I estimate to be in the neighborhood of 2700fps (23.5gn Varget). Sorry I don't have a recorded group size at 600yd but I do have a few ~4" groups (8 round groups) at 400yd and I have many 5rd groups at 300yd that are in the 1.5-2.5" range.

The 77 SMK's are 0.97" long. Don't have any 69gn on hand.

Just to be clear here. This is all just a notice that some of us have had good luck with the 77gn SMK's in the Savage 1:9 barrels. If you want to try it with your rifle, feel free. If not then don't.

In the future I plan on trying to shoot a few groups at 1000yd just to see what happens. According to my ballistic tables the 77gn will still be supersonic at that point so will be an interesting experiment. The problem will be is that my wind dope skills are not very good so.....

it is why i asked the question.
if you are at 1 moa at 400...life at 1000 will pretty much suck.
high power guys go for 1/2 moa

Maybe. Or maybe it is just my shooting ability :)

I shoot a lot of the 75 gr Hornady Match,and Sierra 77 gr SMK's out of my old 12 FLVSS with a 1-9 twist,they shoot great. But,I have never been able to push the 75 gr Hornady A-Max or the newer ELD's fast enough to stabilize for good groups,so I just built a 22 Creedmoor to shoot those bullets.

Have you shot them at distance to see if they are still stable ?

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Originally Posted by varget204

Have you shot them at distance to see if they are still stable ?

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My question would be what’s the point to all this?
I can understand where rules would require a certain caliber or cartridge be used, but otherwise?
The very best 1000 yd benchrest shooters aren’t all using 6mm cartridges for example.
And some who do don’t always use them, depending on conditions.
But if 75% are, does it not make sense that that caliber should win?
So why doesn’t it? At least always?
And as for conditions, go to a match and see how the best of them deal with that, regardless of cartridge.
For the average guy who only cares about reaching out to touch something, say a prairie dog, its best to take about 3 different guns along
and forget about the heavy bullets for the 223.

As I stated, the point is that some of us are having better results with the 77gn SMK bullets (rather than 69gn SMKs) in our Savage barrels, at the distances and velocities we shoot at. Nothing more.

The only reason this has come up is because Sierra says they should not work, so the posts are more of an FYI to others who might not otherwise try them.

There is no claim of anything else. And they are not hunting bullets, just for paper. And no one is claiming they are a good choice out to 1000yd. I will be trying them at that range just for grins, but, I do not expect much.

And, yes, there was at least one person using these for 600yd informal competitiom shooting and doing well with it.


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Quote:

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Originally Posted by charlie b

As I stated, the point is that some of us are having better results with the 77gn SMK bullets (rather than 69gn SMKs) in our Savage barrels, at the distances and velocities we shoot at. Nothing more.

The only reason this has come up is because Sierra says they should not work, so the posts are more of an FYI to others who might not otherwise try them.

There is no claim of anything else. And they are not hunting bullets, just for paper. And no one is claiming they are a good choice out to 1000yd. I will be trying them at that range just for grins, but, I do not expect much.

And, yes, there was at least one person using these for 600yd informal competitiom shooting and doing well with it.


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Well fact is i shoot 69 gr SMK bullets in a factory Savage 9 twist barrel also.
But in a 22x250 AI, not a 223, and they shoot as well as i can shoot them.
Would it be worth my time seeing if 77 gr might shoot as well or better?
Well too each his own, but not in my opinion.
I can see myself using the real heavy 22 caliber bullets in a hot rod wildcat like a 22x243, but without the powder what’s the point?
As for SMKs not being a hunting bullet, don’t be betting anything you cant afford to lose on that, because you for sure will lose it.
Same goes for most if not all the other so called match bullets.
Another little secret as it pertains to (ahem) precision reloading, and factory guns like Savage.
All my SMK (match) bullets come to me in jars, like rinsed out empty large peanut butter jars.
Reason is they are all seconds, sold by the pound at the Sierra store.
Would you like to know what the Sierra employee shooters use?
I mean if they are seconds, are they still SMKs? Why not just trash them and start over?
So lets be sure we get the powder charge to the exact 1/10 of a grain here folks, and the velocity
cant vary by even 5 FPS if we want real accuracy. Lol
Much has to do with mind over matter, and it only matters to those of us who mind.
The main reason I make myself unpopular for saying these things other than it being what i think, is that it would be very easy for the new shooters who haven’t the experience level as yet to be convinced that all this is normal and necessary in the name of accuracy.
Fact is it isn’t, and far from it, at least for the vast majority of us.

Quote:

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Originally Posted by yobuck

Well fact is i shoot 69 gr SMK bullets in a factory Savage 9 twist barrel also.
But in a 22x250 AI, not a 223, and they shoot as well as i can shoot them.
Would it be worth my time seeing if 77 gr might shoot as well or better?
Well too each his own, but not in my opinion.
I can see myself using the real heavy 22 caliber bullets in a hot rod wildcat like a 22x243, but without the powder what’s the point?
As for SMKs not being a hunting bullet, don’t be betting anything you cant afford to lose on that, because you for sure will lose it.
Same goes for most if not all the other so called match bullets.
Another little secret as it pertains to (ahem) precision reloading, and factory guns like Savage.
All my SMK (match) bullets come to me in jars, like rinsed out empty large peanut butter jars.
Reason is they are all seconds, sold by the pound at the Sierra store.
Would you like to know what the Sierra employee shooters use?
I mean if they are seconds, are they still SMKs? Why not just trash them and start over?
So lets be sure we get the powder charge to the exact 1/10 of a grain here folks, and the velocity
cant vary by even 5 FPS if we want real accuracy. Lol
Much has to do with mind over matter, and it only matters to those of us who mind.
The main reason I make myself unpopular for saying these things other than it being what i think, is that it would be very easy for the new shooters who haven’t the experience level as yet to be convinced that all this is normal and necessary in the name of accuracy.
Fact is it isn’t, and far from it, at least for the vast majority of us.

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Well spoken.
Who doesn’t want the best performance of what they have. I would jump straight to a 300 if that was the case. But In my opinion nothing is more fun than shooting the light recoiling .223/ 5.56 cartridge. And talking price point and shooting at mid range.


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Quote:

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Originally Posted by yobuck

Well fact is i shoot 69 gr SMK bullets in a factory Savage 9 twist barrel also.
But in a 22x250 AI, not a 223, and they shoot as well as i can shoot them.....................
The main reason I make myself unpopular for saying these things other than it being what i think, is that it would be very easy for the new shooters who haven’t the experience level as yet to be convinced that all this is normal and necessary in the name of accuracy.
Fact is it isn’t, and far from it, at least for the vast majority of us.

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I guess you miss my point too.

The 77gn bullets shoot better than the 69gn for me in my .223 Axis.

If you don't want to try them then don't. Does not matter to me. I am glad you are happy with what you shoot.

you see why he is on my ignore list.
cannot stay on topic...223/9 twist and 77's
thinks he is better than you because of it.
just an old man lost to the real world.
even the boss noticed his misdirection in a 223 thread.

Quote:

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Originally Posted by charlie b

I guess you miss my point too.

The 77gn bullets shoot better than the 69gn for me in my .223 Axis.

If you don't want to try them then don't. Does not matter to me. I am glad you are happy with what you shoot.

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Look Charlie my comments have nothing to do with whatever bullets you or anyone else want to use.
What ever works well for you works well, what’s to argue about that?
My point was probably missed by you and no doubt others.
A 69 gr bullet, or a 77 gr bullet wont change or improve a 223 anymore than adding 10 ply tires will improve a 1/2 ton pickup.
It’s still a half ton pickup and always will be. You want more truck, buy a 1 ton pickup.
Being an expert at tuning the 1/2 ton, is akin to precision reloading a Win Mag for 2000 yd shooting.
Or 77 gr bullets in a 223 for 1000 yd.
I doubt you will achieve more accuracy with a 223 by using heavy bullets in them regardless of how you load.
As recently say 1990 we wouldn’t even be having this discussion.
Mainly of coarse because there was no internet and sites like this for us to discuss things.
There were also no places where one could go to determine cartridge performance from their Lazy Boy chair.
There is but one thing that has changed the dynamics of long range shooting and hunting.
And it has nothing to do with accurate reloading, high BC bullets, or Lazy Boy chairs.
It’s the only reason we can even be having conversations about shooting any cartridge with whatever bullet at the distances we’ve been discussing. That of coarse is the modern day scopes and mounts.
But because we can, does that also mean its a good thing?
Well i guess a 1/2 ton pickup will always be the most popular, so I’ve probably answered my own question.

https://www.shootingtimes.com/editor...1-review/99098

I’m no scientist but I can read. Sometimes I read things a couple times. I have found that at 600+ yds in a 1-9 barrel you will find no better bullet than the 77gn smk. In a .223 casing or a 5.56 casing.
I’m not talking built guns or crazy cartridges.
A stock gun that ammo is available everywhere, anyone can shoot it.

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None of the heavy tipped bullets are going to be stable in a 1-9. They are just too long to stabilize. Some guns have a hard time with Hornady 68gr also because of the length.

Sierra is a shorter, fatter bullet. That is why it stabilizes. Weight alone is not the single factor. You have to add the length.

Well i cant speak for that, but my guess would be that it has something to do with energy, and knock down power.
I doubt very much they are encouraging the use of that cartridge for long range sniping.
But with regard to that have you read the book written by the Seal sniper Chris Kyle prior to his being killed?
You wont be learning much about shooting or ballistics or get any real insite as to how they, Seal snipers, prepare for a shot.
But you will get his opinion on which of his numerous issued guns he preferred to use and why, and how he personally prepared for a shot.
You might be surprised to learn that his average kill was at a distance of 400 yds. His favorite gun was his 300 Win Mag with the Nightforce
Scope dialed to 400 yds and not changed regardless of the distance. He simply held up or down as the distance required.
With the Win Mag, perfect hits weren’t much of a requirement.
For the very few extreme distance shots he took, he used his issued 338 Lapua.
So while we sit here in our Lazy Boys discussing this stuff, those who are actually doing it might have different opinions.
Yes you can dial a scope to allow for reaching distances beyond that for which any cartridge was designed to be shot.
With perfect conditions, and good shooting you might even have a decent result,
But in 15 minits from now it might be that you cant hit anything.
Which is why the 1000 yd heavy gun world 10 shot record has been stuck at about where it is for about 30 + years.
But eventually, somebody always wins the lottery.

So, yes, this is just about the finding that the 77SMK's (and in CFJunkies case the TMK's) do stabilize in the Savage 1:9 barrels at moderate ranges, AND, they seem to be a bit more accurate for some of us than the other offerings out there. NOTHING ELSE.

For someone else who wants to play with their Savage .223 it is information for them to consider.

None of us claim them to be able to turn a .223 into a magic long range cartridge.

Quote:

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Originally Posted by hamiltonkiler

https://www.shootingtimes.com/editor...1-review/99098

I’m no scientist but I can read. Sometimes I read things a couple times. I have found that at 600+ yds in a 1-9 barrel you will find no better bullet than the 77gn smk. In a .223 casing or a 5.56 casing.
I’m not talking built guns or crazy cartridges.
A stock gun that ammo is available everywhere, anyone can shoot it.

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I read the article and found it to be interesting. Black Hills is a well known ammo supplier for the military, and is the brand used by Chris Kyle to establish his U S kill record.
Certainly if your in the military and have been issued a rifle requiring 5.56mm ammo you would want the best ammo available.
Likewise if your dead set on owning just one rifle for your personal enjoyment.
There were a few words in that rather long article that jumped off the page, at least for me.
Probably most would not have the same reaction as i did however.
Those words were (37.25 minits from a 100 yd zero to reach 1000 yds.
Thats 149 1/4 min. Clicks folks, count the number you have available in your scope with the mount setup you currently have.
Now just for kicks check out say a 6x284 or a 243 with 105 gr bullets, or one of the 6.5s with 140s.
Animals don’t shoot back at us, but if they did very few of us would have enough gonads to hunt them.
The few brave enough to do it would be very selective on their gun choice, and so was Chris Kyle.

any adults that read and comprehend, will note that chris kyle says in his book
that most of his kills were done with a 300 win mag basically some variation of a
mark 13 sniper rifle out of crane. the ammo for the early rifles is military 190 grain with a spec
distance of 1200 yards(now called mk248mod0). the later ammo is a mk248 mod 1, which
features a 220 smk, a federal case, h1000 powder, and a nickle mag primer. it is loaded to aprox 2800 fps
in the short bbl rifles(24") and gets more in the 26.5" bbls. accuracy spec is 1500 yards with a higher 68kpsi.
both federal and bha produced the 190 ammo, but fed got the 220 ammo contract .

You guys keep pulling this further into the weeds.

Up to now almost all of my shooting with the 77gn bullet has been at 100 to 300yd. Previously I have shot the 69gn SMK at 600 and had close to MOA groups but have not been able to break into the sub MOA at that range. Not bad but not great.

I have had two sessions now shooting the 77SMK at 600yd. I have been comparing IMR4166 (21.5gn) and Varget (23.5gn). There is about 100fps difference in muzzle velocity according to book load data. OAL for both is 2.28" They are very close in group sizes at 100yd with the 4166 being a little better by about 0.1" on average (my lack of shooting skill makes this small a difference kind of a wash). FYI I am shooting an Axis HB, 22" barrel in .223 with Boyd's Pro Varmint stock and Vortex 4-16 Diamonback scope. It is not pillar or glass bedded, just bolted into the stock. Shooting is from an inexpensive Caldwell bench rest with a bag at the rear, and a mediocre shooter ;)

The first session was with 4166. At 600yd 5rounds went into 7". No wind at all on that day. At 100yd that same day I had two 5rnd groups of 0.4" and 0.6". Group size at 600 was such that it made me wonder if the bullets were stable. I figured it should be well under MOA.

Today I had the Varget load set up at 100, 400, 500 and 600yd. Wind started light then went to a little gusty, 6-9mph at 45deg to the bullet path. At 400yd and light wind 4 rnds went into a 1.8" group. At 500 yd and light wind 5rnds went into a 3.5" group. At 600yd the wind had picked up. I held off by 6" to account for the wind. The horizontal group size was 5.2". The vertical group size was 2.7". At 100yd with the gusty wind I had three 5rnd groups of 0.4, 0.8 and 0.9".

I was not trying to figure out the gusts of wind. At our range it may be a low point in the turbulence at the bench but the wind flags show significant wind ast range. I set my wind hold at a 'median' point and shoot a string, without waiting for a 'calm' point. I know this is not a good technique but I am a relative novice to wind doping at medium and longer range.

So, for me at least, I will venture a guess that the 77gn bullet is stabilized out to 600yd. Is it stable further out? According to theory it should be stable as long as it is supersonic, which for this load is just beyond 1000yd. I will shoot it at 1000 just for grins but that is not my goal. My goal is to have an accurate shooter at 600yd and so far the 77 SMK's are working the best.

Nice work, charlie b.
Thanks for the good reporting.

Shooting in a brisk wind with a relatively light bullet is really challenging.

Thanks. I don't mind a steady wind but when it is turbulent it is a pain ;)

Quote:

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Originally Posted by charlie b

Thanks. I don't mind a steady wind but when it is turbulent it is a pain ;)

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Well Charlie i’ll Stick my head out of the weeds again just long enough to say there may be ways to deal with that.
As Yogi would say, when you come to a fork in the road, take it. Lol
If you were to visit the website for “the original 1000 yd benchrest club”, commonly referred to as the Williamsport club, you can look at the equipment list of the various shooters as for gun and scope, as well as the name of the gunsmith who built the gun.
Remember, that club was the first in the world to shoot bench rest matches at 1000 yds.
There were no rules applying to it at that time so they made up their own.
Thats now been over 50 years ago, and although there have become quite a few other 1000 yd clubs around the country, most of them run under NBRSA rules.
But not Williamsport, and i believe one or two others. They shoot ten shots for record regardless of wether it’s light or heavy gun, which would be the main difference in rules.
If you were to check the stats of the “world open shoot” held in July, you would find that by far the most popular cartridge used today is the 6mm Dasher. And you will also find that a very high percentage of the ones used in that match were built by the same gunsmith.
Beyond that, many of those shoot the same load using the same brand custom bullets.
Point is, there really isn’t much difference separating many of the shooters as for equipment and/or ability.
But there can be a major difference in the shooting conditions during the time frame of the relay they were drawn for.
So, that means it can actually come down to the luck of the draw, or the lottery if you will to a very large degree as to who wins and who doesn’t.
BUT, people being people, and always looking for ways to improve their own chances, have developed ways of dealing with it at least to a degree. The big thing that evolved as a result, is beating the wind, And that requires shooting ten single loaded shots asap, like in less than a minit.
And in order to accomplish that, it requires a very expensive joy stick controlled front rest along with lots of practice.
But of coarse that could lead to questions about the best gun, load, shooter, etc. couldn’t it?
Have we become better? Or better at beating the system? I guess it makes little difference if the goal is winning.
Again Charlie, you may well be at a fork in the road.


’

LOL yeah I think you are correct. When I look at benchrest competition I see lines of flags from bench to target, and that's for 100 or 200yd, not long range. I did watch them check the wind and sights carefully and then run 10 as fast as they can.

At our range I put up some ribbons at each of the target stands (every 100yd). So, I can at least see the difference along the range. Problem is they are frequently different second to second. Left at 100, right at 300, left again at 500, calm at 800, etc, etc. Next couple of seconds and every thing shifts.

I WILL get better at this!!!! I insist. :) FWIW, I am not competing, except with myself. After I check this one at the longer ranges I will go back to a bipod and rear soft bag. What I like to do is 'plink' at soda cans at 600yd :) I also have two small gongs I sometimes set up (4" and 6") at different target stations to shoot at. The down side is I cannot measure group sizes when I do this, but, it is much more fun to see the cans explode :)

Had a very good day at the range today, except for my 600yd target :( No wind at all and then it worked up to about 2mph :) This series was all fired from a Harris bipod with a rear bag, my 'normal' shooting setup for this rifle.

At 200yd I fired two fouling shots, then two to check zero. Adjusted windage and then an 8 round group that ended up being 0.9" Not bad for me.

Set to my 600yd dope and fired a shot at my 6" gong. Hit it dead center. Then fired a 5 round group that was horrible, around 10". I did not know how bad until I went and looked at the target. I have no idea what I did, but, it was bad.

I then shot a bunch of 'plinkers'. Soda cans, gong, etc at various ranges from 200 to 600.

Then I decided to try 1000yd. Wind was 1-2mph so it was a perfect day for this. I checked my ballistic calculator and it said 33.5MOA up from my 100yd zero setting. I started turning the turret on my scope, two full turns plus the 3.5. There is a berm with some white rocks on it I can see impacts. So, I fired one. About 2 ft low so moved the setting up and fired again. About 10" high. Down a bit. Hit just to the left of the rock about 6"!! Then fired 15 more rounds at that setting (+36MOA). There was a 12" gong out there so I shot at it. All but 4 rounds hit the gong with the misses just off the left edge by a few inches.

This satisfies me that the 77gn bullet is stable out to 1000yd. Based on bullet drop the muzzle velocity is just under 2700fps (2690?).

It also encourages me to keep shooting at the longer ranges. :)

PS I was also surprised that my scope had enough adjustment range for this as I never checked he specs on it.

That is great information. I am happy to see the 77s maintain their stability out that far.
I post a like but apparently that feature has died with the new server.
Sound like you had some fun testing. That is the most important thing.

Last post in this thread for me. Had another good day at the range. I also had some of my new Lapua brass loaded up. Same load, 77SMKs, 23.5gn Varget, Rem BR primers. Shooting off a Harris bipod with rear bag.

Shot a group at 200 yd just to warm up a bit. 1.5". Adjusted windage just a bit.

At 600 yd 5 round group was 3.9" Not too bad for me.

Then 1000yd again. The wind was not bad but was swirling, 2-3.5mph. At 1000yd that translates into about 20-30in of windage. Took me 10 shots to get windage and elevation just right. Then yook some shots at a milk jug I had out there. Took me 8 rounds to hit it. Just to the left, just to the right, little low, little high, repeat. Hit it half way up on the right hand side (wind was left to right). I also shot a 10 round group which measured 18". I consider that a success considering the wind being good for 5-10" of that.

Two other guys were shooting a 10" gong at 1000 with their custom chassis 300 Win Mags. They were only hitting every other shot so I didn't feel too bad :)

NO, this is NOT a 1000yd target bullet. BUT, it is stable out that far. I am impressed at how well that little bullet does at range.

PS when it did hit the milk jug full of water it was not impressive. It jumped slightly but no big explosion like at closer ranges.

Having read this thread I thought I too would try 77 TMKS in my 12fv.
For reference my pet load is 69SMKs at 24.6 grains of Varget. Consieved accidentally as they turned out a COAL 2.237 VS the 2.298 I had intended. They shoot very well. Less then .5moa at 100 and under 1 moa at 200.

So today I gave the 77 TMKS a try. With ten thousands jump the COAL is 2.385. Powder was 21.8 and 22.0 varget.

Accuracy at 100 yards was good. Matching my 69s. With only a few rounds left I tried the 77s with 21.8g varget a try. Oh boy, they sank like rocks and the group really opened up.

So I'll load some up at 22.5 next time out.

How did everyone else do when moving out past 100 yards?

Quote:

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Originally Posted by TommyD11730

Having read this thread I thought I too would try 77 TMKS in my 12fv.
For reference my pet load is 69SMKs at 24.6 grains of Varget. Consieved accidentally as they turned out a COAL 2.237 VS the 2.298 I had intended. They shoot very well. Less then .5moa at 100 and under 1 moa at 200.

So today I gave the 77 TMKS a try. With ten thousands jump the COAL is 2.385. Powder was 21.8 and 22.0 varget.

Accuracy at 100 yards was good. Matching my 69s. With only a few rounds left I tried the 77s with 21.8g varget a try. Oh boy, they sank like rocks and the group really opened up.

So I'll load some up at 22.5 next time out.

How did everyone else do when moving out past 100 yards?

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I don’t reload. I shoot a standard mk262 mod 1 load. They are still .5moa at 500yds with no wind. 2.5-3” groups all day. Ringing 10” plates at 700yds.


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FWIW, the above loads were 23.5gn Varget with 77smk in my 22" Axis heavy barrel running 2800fps.

Quote:

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Originally Posted by charlie b

FWIW, the above loads were 23.5gn Varget with 77smk in my 22" Axis heavy barrel running 2800fps.

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At a COAL of 2.28?

Looks like I have plenty of headroom in terms of my powder charge.

Thank you sir.

with my 12 FV .223, my best loads are seated at 2.296 to 2.305 C.O.A..L. with the 77 SMKs.
For the 77 TMKs my best loads are seated at 2.339 to 2.342 C.O.A.L.

But my chamber has over 3,000 rounds down the tube.

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