6mm / .243 guys - I need a hand with this.

My .243 with the 26" stainless is more temperamental than my 3rd ex-wife. I have great accuracy loads for 55 Nos BT's, 70gr Nos BT's and Sierra MK's & 75gr Hornady SST's. To obtain these I really had to bust my aggots. By the way, this is one of those barrels you may have heard me mention..... I can shoot it for the day, come home & clean it & there's hardly ANY copper in it. Lots 'o carbon. Very little copper.

Which brings me to my question....

I can't get the 90gr Nosler BT's to obtain any degree of consistency or accuracy. Our resident bacon fanatic Dean / scope eye has recently impressed on me the necessity of speed in some cases.

I've used H4831 with some results (1" red dot at 100 yds has a bunch of holes) BUT, I'm just not happy until they ALL go thru the same hole at 100yds. Then , I'll tune it for long distance reaching out and touching someone.

What powder you guys using?

I got fast stuff, I got slow stuff & I got stuff in between.
This will be Frank's Obsession for the week.

Thanks.
Frank in Fla

PS - Before anyone asks, it's a 1 in 10 twist.

OK problem child 45gr of IMR4350 will put you where you want to be with those 90s, that or as much RL19 as you can stuff in to that case, repeat after me a compressed load is a happy load.LOL

Dean

I tried 4350 & RL-19 which, I might add, are regular powders here. They both sucked in my .243 with the 90gr Nos BT's....

As far as loading, according to you I should fill the case, drive the bullet in with my 4lb. steel hammer, say a brief prayer & pull the trigger. From there, work backwards until I find the sweet spot.

Lastly, my friend from my former home, I'm working on a "special little something" for you. DON'T GET ME PO'ed......

What else ya got beside the 4350 or RL-19 loaded hot? You know I hate compressed loads.

How much have you messed with seating depth? Have you changed primers?

Actually my best loads in a 26" barrel Savage .243 came with H1000 and the 95gr Sierra match bullet. Read about the load on accurateshooter.com and went with it. I think I still have the load data if you want it.

No prayers needed those are very slow powders and no hammer needed, just pull up the ram slowly give the powder time to compress, but if that is not you cup of tea try.
42gr H380
38gr 4064
38gr Varget
38gr H4895

Spanky

Hey Dean - Let me ask you this. I had some 105 & 115 VLD's I tried & could not get them to twist fast enough with the 1 in 10 barrel. Is it possible maybe it doesn't like anything heavier than 75 - 80gr?

When I tried the 115 VLD's, the ones that actually hit the target went thru sideways. Out of 10 rounds, 4 of the 10 actually hit the target. I have to admit, it was kinda funny seeing the bullet hole looking like the bullet silhouette.

Whatcha think?

Quote:

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Originally Posted by stomp442

How much have you messed with seating depth? Have you changed primers?

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Seating depth always starts at around .030" then I close in for the sweet spot.

I thought about primers & used CCI & WLR. Same result. Don't get me wrong guys. It will shoot 1" or less at 100yds but as I said earlier, I like one holers. This way I know I'm good to go at 400 or 500 yds. This has been a challenge with the 90's.

Edit - I just looked on the Nosler Reloading site. It's saying H4831 was the most accurate powder tested. The best I've been able to get was with 43.8 to 44.0gr of 4831.
Maybe I should go back to square one with that powder & have another go at it?.....
Perhaps try a different brass with it or change up the load sequence.

Frank, are you crimping the bullets in place or relying on neck tension only?

Almost of all of my barrels and calibers I do not crimp. However, with a 22-250 1-12" twist barrel (I recently let go to a buddy) if I just seated the bullets with no crimp I would get .75" @ 100yds reliably, but if I would give them a light squeeze in a Lee Factory Crimp Die it would instantly shrink the group to the .250 to .375" range. Maybe something to try if all else fails.

Frank if you don't have a chono, you need to invest in one, and those 90s with 44gr of 4831 in a 10 twist at 2800fps are just on they edge of stability,
and as far as those 105, and 115s, ain't never going to happen they would need to be traveling at least 3300fps in a 10 twist.

Dean

Quote:

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Originally Posted by scope eye

Frank if you don't have a chono, you need to invest in one, and those 90s with 44gr of 4831 in a 10 twist at 2800fps are just on they edge of stability,
and as far as those 105, and 115s, ain't never going to happen they would need to be traveling at least 3300fps in a 10 twist.

Dean

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Yeah I found that out. the barrel was supposed to be a 1 in 8 twist. When I mentioned it to the guy I bought it from he offered to take it back but I declined since I already had some loads worked up.
Chrono - It's on the list of required acquisitions..... Many times I run into guys I know at the range & use their chrono for a few round just to see how an accurate load if doing. That's how I found out my 223wssm was hitting 4400fps with 69gr custom comps. that was a max velocity.

Quote:

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Originally Posted by bootsmcguire

Frank, are you crimping the bullets in place or relying on neck tension only?

Almost of all of my barrels and calibers I do not crimp. However, with a 22-250 1-12" twist barrel (I recently let go to a buddy) if I just seated the bullets with no crimp I would get .75" @ 100yds reliably, but if I would give them a light squeeze in a Lee Factory Crimp Die it would instantly shrink the group to the .250 to .375" range. Maybe something to try if all else fails.

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No Boots, I never relied on crimping. I am rather particular with neck tension. I have different diameter mandrels for my sizing dies so I can experiment with neck tension. I'd say about 98% of the time a light neck tension work best for all my rifles. Light being under .002" - (.0015 or less). I have even taken a bullet, press it in the neck, pull it out & load the brass with a very light neck tension. My 7mm-08 worked best that way. Almost 0 neck tension.
As far as crimping- I have heard other guys mention that. A good crimp closed the group up. After looking over some old notes & targets, I'm going to try the H4831 recipe again. I had some results with it but not consistent enough for me. This time I'll pay more attention to details like COL, neck size, etc. maybe this is one of those barrels that doesn't easily please.

Uh oh.....
I think I may have found out what happened. It all started with me being STOOPID.

Back in 10/20/12 - the first batch I put together for testing with H4831, I wrote a COL of 2.766". I had reasonably moderately OK results with 43.8gr of 4831.

The next time I loaded some up for fine tuning, I did my famous "reverse the numbers trick". My notes from 12/22/12 show I wrote down 2.677" COL. A slight variation of .089".

Maybe, just maybe that was what caused the inconsistency in grouping. Like I mentioned, 5 rounds would fit inside the 1" red dot on the target, just not consistently. I have the original target from 10/20/12 which shows a pretty tight looking 4 round raggedy hole using 43.8gr of 4831. All targets from 12/22/12 and beyond show loose grouping with a flyer of two per 5 round test .

SO.....

To summarize, I believe I screwed up with reversing the COL numbers. I just finished loading up the test sequence charges with the first COL of 2.766". Should this be the reason for the loose grouping (and I'm pretty sure it is) please feel free to verbally abuse me.
I'm glad I didn't reverse the powder weight numbers. (34.8 instead of 43.8.....)

Geeeeezzz I really hate getting old(er). The 'ol memory is the 2nd thing to go, so they say. I can't remember what the 1st thing is.

To be continued.

Hey Frank this is what is happening as far as your bullets are concerned, all things being equal a heavy bullet needs to spin faster not necessarily go faster, although there is a correlation between the two back to that later, a heavy bullet will have a long bearing surface and you need to SPIN them fast to stabilize them, between 225,000 rpm on the low side and 275,000 rpm on the high side, the faster you can spin them the further you can shoot them, without them starting to tumble or drift, lets take your 90gr load with 44gr of 4831 and 10 twist barrel, that load was probably producing a speed of 2800 fps
2800 X 720 div 10 twist = 201,600 RPM way out of the parameter,
2900 X 720 div 10 twist = 208,800 RPM
3000 X 720 div 10 twist = 216,800 RPM you could maybe get away with this for a short distance,
3100 X 720 div 10 twist = 223,200 RPM that's the MIN you need for 90s 105s and 115s
2800 X 720 div 9 twist = 224,000 RPM for 1 inch of twist = 10% less speed needed,
2800 X 720 div 8 twist = 252,000 RPM that is what you need for 500 to 1000 yards,
if you can find a way to send those bullets faster, you would be fine with a 10 twist, It's hard to accomplish with a 243 without seeing pressure signs, you would need to AI it or rechamber it to something that holds more powder volume, like a 6mm-06 to get the speeds you need to compensate for the 10 twist, heck it can be done I send 105s with authority, in my 6mm-06 AI in 12 twist but @ 3650 FPS so it can be done.
This applies for heavy bullets, light bullets with short bearing surfaces traveling at a high rate of speed, can get away with RPM speeds well under 200,000 RPM, I have send stuff over 5000 FPS out of my 220 swift AI
that has a 16 twist, and that's not a typo.

Dean

I read a lengthy article on bullet weight in relation to barrel twist & velocity. I think it was just a few months ago when I tried the 105 & 117gr VLD's. After seeing the bullet hole the same length as the bullet (from going thru the target sideways) I did a bunch of research / reading on the subject so I'm pretty clear on that subject. Just as clear as mud....... just kidding.

Just the same, I'll be giving it the 'ol college try once more. Thus time I have a consistent COL and charges are up to maximum with the H4831 - 48.0gr according to Mr. Lyman & the Hodgdon Annual Manual.
From the reload manuals I have, it appears as though 3000fps is the magic number. Many of the charges show 3000 + fps for best results. I'm thinking worst case scenario - I can settle for a .80" to 1.00" group at 100yds if I have to. If greater accuracy in needed for a longer distance well...... That's why God made the 25.06.

I'm feeling kinda lucky today. Maybe this will be the day I get that elusive 5 round .5" group. I'm getting ready to hot shoe it down to the range in a few minutes. Temp is 87* now with 163% humidity. The air feels like I'm walking thru warm bath water. Rain in the forecast today. Again. I'll keep you posted on the situation.
Thanks again for your assistance .

Well, I'm a bit envious.

My stock Savage accustock .243 shoots the 80 gr Nos BT's and 75 Hdy V-Max's really well, with a variety of powders. But, drop the bullet weight down to 70 grs - Nos BT's or SMK's and it turns really finicky..........

Quote:

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Originally Posted by beartooth91

Well, I'm a bit envious.

My stock Savage accustock .243 shoots the 80 gr Nos BT's and 75 Hdy V-Max's really well, with a variety of powders. But, drop the bullet weight down to 70 grs - Nos BT's or SMK's and it turns really finicky..........

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Rather odd how that works, isn't it? One bullet will be very impressive then, go up or down 5 or 10gr & you'd be better off throwing the bullet instead of shooting it.

Then, there's the occasional bullet that just can't be made happy. No matter what you try, it will not settle down.

But ya still gotta love loading yer own goodies. Regardless of the results.

Frank, maybe you just need to do like Dean and rechamber that ol' barrel to a 6/06AI or go like me and go 6mm-WSM. That should give you all the speed ever needed to get those bullets to stabilize. Plus in that heavy humidity you got down there you would most likely get some wicked vapor trails. LOL.

All jokin' aside hope that your failing memory is the culprit this time. ;)