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I've looked through several other threads in hopes of finding some details but did not find them. Sorry for any duplicity on my part. I see lots of talk about the H4350 powder as well as the IMR4451. Most of the bullets being discussed are the 140's or even the 129 gr. Has anyone had good luck with the heavier 143's or even the 147's? We have shot the ELDX and ELDM in other rifles and they're great.
I would only use 143 for hunting, 147 match for target. Grab either powder and bullet and get to it.
142's are doing fine .
Just asking about a bullet weight or a powder really can result in really misleading answers.
You might get told about the best group, the best load or the best average but posters rarely state what they chose to express their opinions.
In addition, the data listed below shows that two Savage 6.5mm rifles have different results and have different preferences.
I would suggest you try different weights and powders with your rifle and shoot enough groups to get a statistically valid sample of each load and then concentrate on what you find works best in your rifle.
At the risk of overloading you with information, I think this long answer might give you what you need to be looking at.
Taking the average of all the groups shot with a bullet weight regardless of powder used:
I have one Savage 6.5mm CM (Model 12 LRP) that shoots 147 ELD-Ms best, then 130 TMKs & TGKs 1.6% worse and 142 SMKs slightly worse by a 8.6% margin.
123 SMKs shoot 27.1% worse.
But by individual bullet they rank as follows with increases in average group size: 130 TGK (0.0%), 147 ELD-M (4.0%), 140 ELD_M (7.2%), 130 TMK (12.3%), 142 SMK (13.4%), 140 Berger Match (16.6%), 140 Berger LR (19.6%), 140 Berger Hybrid (23.7%), 140 SMK (27%), 123 SMK (32.26%), 143 ELD-X (45.7 %).
Taking the average of all the groups shot with a particular powder regardless of bullet used, it likes IMR4451 Enduron best, IMR4350 second by 11.7%, and RL-17 next by 13.8%.
However, for the 10 best loads shot by that rifle:Again taking the average of all the groups shot with a bullet weight regardless of powder used:
The first rifle has 142 SMKs in 1st(IMR4451) & 3rd(IMR4350)
140 ELD-Ms in 2nd (IMR4350), 4th & 5th (IMR4451), 8th & 9th (IMR4451)
147 ELD-Ms in 6th (IMR4451)
130 TMKs in 10th (IMR4451)
Considering that data, how would you answer your question?
But that is only one particular rifle. Can that data match what happens with a different rifle.
I have another Savage 6.5mm CM (Model 10T-SR) that shoots 130 TMKs better than anything else. It shoots 142 SMKs second best by 6.0%,140 ELD-Ms slightly worse by 68&%, 147 ELD-Ms by 7.8%, and 140 SMKs the absolute worst by 29.9%.
But by individual bullet they rank as follows with increases in average group size: 130 TMK (0.0%), 140 Berger Hybrid (3.2%), 130 Hornady ELD_M (3.4%), 142 SMK (6.0%), 140 Berger Match (6,1%), 140 ELD-M (6.8%), 143 ELD-X (16.3%), 140 SMK (29.9%), 140 Berger LR (40.0%)it likes IMR4451 best, IMR4350 second by 4.0%, and RL17 third by 21.3%.
Taking the average of all the groups shot with a particular powder regardless of bullet used,
However, for the 10 best loads shot with that rifle:RL-17 has the 17th best load with 130 TMKs and is the only RL-17 in the top 25 loads.
The second rifle has 140 ELD-Ms in 1st (IMR4451), 2nd (IMR4350), 6th (IMR4451), 9th IMR4451) & 10th (IMR4350)
130 TMKs in 3rdth (IMR4350), 5th (IMR4451), 7th &8th (IMR4350)
143 ELD-Xs in 4th (IMR4350)
I think the data shows that there is no simple answer to your question.
You'll never know what works best with your rifle until you test it.
how many rounds of each bullet weight/ manufacture/ and powder do you shoot to get good useable data? I load for a 308 and still have not found the magic combo after loss of rounds down range.
CFJunkie, thanks for sharing your information. I sure it cost a lot of man hours and money to arrive at the statistics you shared, it gives me a baseline to start with and some good insight.
Good point. CF is definitely a student of accuracy. Often long range shooters are looking for nodes. Concentrating on a certain velocity target. I have found this too be a good process but there are many exceptions to that rule.Quote:
Originally Posted by DesertDug
How many groups do I shoot before I begin to make decisions?
Twenty groups gives a very good statistical basis for a decision, but if the standard deviation is small, I will begin to focus with 10.
I load around specific velocities that seem to suit each rifle best and account for the velocity variations due to trim length and seating depth so groups with the same bullet and powder within a few fps of planned velocity give a good indication of the effectiveness of the load. It doesn't take long to get a good sample for a powder bullet combination.
I load in 0.1 grain increments once I get honed in on a velocity that I want and watch to see how the accuracy increases or degrades as the velocity changes.
I load for 7 rifle calibers but tend to focus most on my most accurate rifles - the two Savage 6.5mm Creedmoor rifles that I cited in post #4, a Les Baer Super Varmint 1:8 twist .223, two Savage model 10 .308s, and a Savage model 11 .22-250.
I have also shot a lot with a CZ 527 Varmint .223 but it is getting old after almost 7,000 rounds.
I tried it the other day with the new 60 grain TMK and it performed pretty well so I am loading another 75 rounds to see how well it might do with another powder.
It seems I can always find a new bullet or powder to check out and using a rifle that you know well is a good place to start with a new variable.
I burned out a barrel with my original Savage .308 trying to find 'nodes' without really understanding the dynamics of the process and, although I kept good records, I wasn't an experienced enough shooter or reloader to take 'shooter and reloader induced variations' out of the process. After many years, I've had enough time behind the trigger and with a hand on the press lever to get that sorted out.
Now if age doesn't catch up on me too quickly - I'm 75 but still going strong - I'm hoping to get a couple of new rifles and continue the learning experience.
CFJunkie, do you have a universal number that you use for the overall length of your bullets. I was wondering if you have played with seating the bullet at different distances from the rifling. I have found some bullets that work better a couple of thousands off the lands and others that work better just touching the lands. Where you have experimented with so many different bullets with the same guns and same basic loads I was curious if you have found a magic answer to overall length when it comes to determining seating depth?
I vary the seating depth quite a bit when I am trying to find what works for particular a bullet.
However, I stay away from seating a bullet into the rifling because I don't want the initial surge in pressure that it causes.
I used to be a believer in finding the optimum jump distance to the rifling.
I experimented with 'bullet jump' a lot and my conclusion was that there is no 'magic number' that applies to all bullets with a particular rifle.
I have found that certain powder-bullet combinations produce better results than others because one combination of burn rate and bullet characteristics fit a particular barrel more than others. Some of that depends upon the amount of bullet body in contact with the rifling.
I have found from varying the bullet seating depth that there wasn't as much impact in accuracy as I expected, at least for my best shooting rifles.
Then again, I have found that certain velocities work really well in each rifle and if I stay close to that velocity, most everything else doesn't make as much of a difference.
Im sure glad I bought more 4451 on the last sale. It works well in my 12fv 6.5cm, and CFJunkie has the data to back it up:cool: ha ha
And the irony of this reality is that by the time you've figured it out your barrel will be shot out and will need to be replaced - requiring you to start all over again.Quote:
Originally Posted by CFJunkie
BTW, you wouldn't by chance be related to the infamous Art Hammer would you CFJunkie? He's the only other person I know who goes to such great lengths to collect and interpret load data, though his preference is the .220 Swift.
CFJunky, you make me pause and question my self. I do not have a conograph to test velocity of my loads. I typically load up a bullet and check weights of powder. Find the one that groups best and then fine tune overall length.
You seem to to be more focused on velocity? Why is this the driving factor?
After reading this long post, you probably will regret asking the question, but here is the answer. I'll only hit the highlights because it would take about 10 pages to provide the data to substantiate the conclusions.
In November 2014 I found an old article by Christopher Long entitled “Shock Wave Theory – Rifle Internal Ballistics, Longitudinal Shock Waves, and Shot Dispersion”, written in 2004, that described the theory of how shock waves in a rifle barrel might change accuracy. It seemed to be a reasonable idea but there were no documented results in the report that proved that the theory had merit, so I decided to try testing to determine if the theory might work. I finally started to load ammo tuned for exit time early in 2015.
The theory is based upon the fact that as a round fires, the barrel chamber swells because of the explosion of the powder. The shock wave bulge from that explosion proceeds down the barrel from the chamber towards the muzzle. The speed of the shockwave and its subsequent reflections is affected by the type of steel in the barrel and its length, including attached muzzle devices. When the shock wave is at the muzzle, it expands the crown slightly and that was theorized to cause a slight degradation in accuracy.
The objective is to load a round, with the powder charge chosen to keep within the minimum and maximum recommended loads for the bullet and powder being used, so the reflection is at the chamber as the bullet exits. To do that, the powder, charge, bullet, case trim length, seating O.A.L. are tuned so the bullet exit time matches the time when the reflection will be at the chamber. The exit time is estimated in microseconds (thousandths of milliseconds) and varies by barrel length and the type of steel (reflection speed increases with the percentage of carbon making up the steel mixture).
To find the right velocity, you need to know the exact length of the barrel, including the muzzle brakes, flash hiders, etc. and the type of steel in the barrel so you can calculate the reflection speed. A classic old barrel has a reflection speed of 18,916 fps. A 3% carbon steel barrel (most of the Savage barrels) has a reflection speed of 19,107 fps. Barrels of 4140 and 4150 stainless steel have a reflection speed of 19, 969 fps and 416R stainless steel has a reflection speed of 20,014 fps.
Once you know the reflection speed in the steel in your barrel and apply it to the length of the barrel you can calculate which reflection to use ( the shock wave goes up and down the barrel after you fire and as the bullet is proceeding down the barrel). For example, a 24-inch Savage 3 % carbon steel barrel takes 1.256 msec. to make 12 reflections. That is in the range of the amount of time that a bullet exits the barrel with a powder charge within the minimum and maximum charges to stay within PMax. One of my 'nominal' 24-inch Savage barrels is 24.156 inches so the reflection time is slower.
My 18-inch Les Baer 416 R stainless steel barrel has a reflection of 0.899 msec. at the 12th reflection so I have to be really careful to stay within the PMax with most powders. For the most energetic powders, I have to use the 14th reflection of 1.049 msec.
You choose a powder charge, trim length, and seating depth to get the bullet to exit around the reflection time for each of your barrels.
Comparing results when shooting loads that were with 0.010 msec. of the reflection time with loads further away from the desired exit time, the improvement in average group size measured between from 0.052 to 0.177 inches across my 5 most used rifles with a weighted average of 0.117 inches.
With my most accurate rifle, the Savage 12 LRP 6.5mm Creedmoor, the difference is 0.069 inches. That means a 19% savings in average group size when the loads are tuned for 'bullet exit time'.
I find that using this technique with a new rifle minimizes the time it takes to get to the best loads.
Two of my shooting buddies have adopted the technique and also have found they get to an optimum load set more quickly.
J. Baker is right that you can wear out a barrel before you find what works.
When I started to reload years ago, I was fumbling around with powders, bullets, bullet weights, seating depths, etc. without a clue about what I was doing.
By the time I got a couple of things right and got consistently better results, I had shot over 6,500 rounds through my first Savage .308 and had to have the barrel replaced.
After that experience, I took what I had learned and seriously reduced the time with my newer rifles to get good results more quickly.
With the latest rifles, I was in the right zone almost immediately.
I haven't worn out another rifle yet, and I have quite a few of them and I get pretty good results with the majority of them.
J. Baker
I am not related to Art Hammer.
I am a retired engineer who has a real fascination with causal analysis.
I just applied my experience with analysis to find consistent results from the complex systems designs I was working on over the years to the results of my shooting.
It's just second nature for me to try to tune everything so it works better.
My asking if you were related to Art was a little tongue in cheek as you two would be like two peas in a pod with your in-depth and scientific approaches to reloading. Art is a bonafide mathematical genius and process improvement expert. He used to frequent our forum quite regularly in years past, but sadly he's been noticeably absent in recent years. Last I heard he had moved to the Phoenix area and was putting together a benchrest rifle, but that's been a year or two ago.Quote:
Originally Posted by CFJunkie
thanks! Anyway to calculate speed without crono?Quote:
Originally Posted by CFJunkie
I guess you are using the muzzle speed of the test load to calculate if you are exiting at the reflection time.
This is is all well beyond my reloading level at this point but very interesting and helps with understanding in the search of accuracy.
J.Baker
I figured you were tongue in cheek.
I would have liked to study some of his posts.
I think I would have appreciated his knowledge and approaches and learned something from him.
I hope I can contribute a little too.
DesertDug,
If you use QuickLOAD like I do, it can give you a pretty good starting point, especially when you adjust for trim length, seating depth, and temperatures.
(Temperature adjustments don't work in QuickLOAD for Extreme powders so I adjust for that myself.)
QuickLOAD calculates exit time for each load considering the characteristics of the different powders.
(The powder burn rate actually effects the acceleration of the bullet at ignition and has to be considered it determining the exit time.)
A chronograph allows you to confirm that you got the load right around the muzzle velocity you predicted and allows you to adjust accordingly.
A chronograph can't be close the muzzle because the shock wave can give you a false trigger so you have to account for the 12 to 18 feet distance when you try to determine muzzle velocity.
Also, reloading isn't an exact practice and you will always have a variation in measured velocity of 5 to 7 fps no matter how well you reload but that variation is within +/- 0.002 msec. so it hardly matters as long as the median is around the desired velocity.
The variation is due to the built in measurement errors in even the best scales, variations in pressure when using calipers, variations in neck tension from one brass neck to another, and variations in bullet weight.
It is amazing that with everything that can go wrong, the results as good as they are.
Maybe the Lab Radar or the magnetic chronograph might be better for measurements at the muzzle, but I have a Oehler 35P so I have to adjust for the distance from the muzzle to the first sensor of the chronograph.
There are two sensor sections on the Oehler 35P in a 4 foot section and you can see a couple of fps loss even over that short distance.
I too am an engineer and can relate to what CFJunkie is saying. Loading ammo and precision shooting is the ultimate activity for folks who like to observe, gather data, interpret it, and make things work better. I can envision myself diving much deeper into this when I retire in a few years.
Some cautions about QL if your aren't actually measuring pressure to be able to "adjust" things to make it match your expectations.
From my testing, Thales powders and Groupe SNPE seem to give Hartmut anything he wants. He gets essentially nothing from General Dynamics. QL's predictions can be very dangerously wrong about much of the newer sphericals, and flat can't understand the progressive burning powders.
I'm just a dumb cop, but I like for all of my fired bullets to make a tiny, little hole in the target! :rolleyes:
I doubt the dumb part. Cops are generally curious and want to understand what's happening, part of the job:cool:
Pressure testing just took a big price jump, but still coats less than a new Savage and glass.
Just remember advertisements directed at emotion, are likely full of something. Whether they tell you it's "extreme" or has no r-bst, or that it's GMO free; it's a sales pitch, not a disclosure statement.