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Posted: 8/9/2011 8:44:34 AM EDT
[Last Edit: 8/10/2011 9:48:01 AM EDT by 308Sako]
Mine are based on the optimal barrel time theory.


And that combined with optimal charge weight as found here:


I have been reloading ammunition for many years and have seen some great successes and some great failures.

That said here is my current method for attaining best possible consistency with my reloads for the AR 15 caliber .223 or 5.56 NATO.

Read this twice please: Only change one thing at a time. Yes, only one variable or you will not know which change caused a difference to occur.



Using the picture above as an example I strongly urge you to record the case dimensions for all the points shown. First for the case un-fired, then fired, then re-sized and last in the loaded configuration. The purpose is to determine exactly what changes are occurring to the brass during it's usage. This will also show you how much your dies are doing, and where they are working the brass.

I use one lot of quality brass be it Lapua, Winchester, Federal or Lake City matching date and head stamps. I always refer to loading manuals, yes manual(s) plural to establish which powder(s) should give the best possible velocity and case capacity. Then I begin with the starting recommended loads and work a progression of charges trying to be under 1% of the total charge weight for the cartridge. If the maximum charge is 25 grains, then I would use a 2/10ths of a grain interval. This amount usually amounts to a velocity gain of about 20+ feet per second, and if my rounds are uniform outside of the standard velocity variation for the load. Hence a different node.

I try to use brass which has been fired once in my rifle and had the headspace or shoulder bump controlled to -.002" +/- .0005" I do uniform and clean my primer pockets, and I try to have my brass trimmed to the same length. I use the Redding bushing dies because I am a strong believer in uniform neck tension. The pursuit of uniform neck tension has recently made me a convert to the annealing process which enormously helps achieve that goal. You will feel the difference the very first time, do it!

Components and equipment; if you don't use the best quality bullets, how can you expect best ever performance? Same can be said for the rifle and sights and trigger, but I am trying to limit this to the reload itself.

Last I would add that I believe that there is no one load that is good in all rifles, but there is one load that will be best in yours.
Link Posted: 8/10/2011 9:48:34 AM EDT
Bump, no one cares or knows any?
Link Posted: 8/10/2011 10:28:58 AM EDT
Originally Posted By 308Sako:
Bump, no one cares or knows any?


Don't get high on your own supply?

Chris
Link Posted: 8/10/2011 10:58:23 AM EDT
Link Posted: 8/10/2011 2:04:38 PM EDT
Some interesting stuff there Sako, and definitly a lot to read. Have you found the OBT to hold true for you in .223/5.56?

I could definitly see where this would be something to look at in 308 or .223 for long range (say 400-600yds, thinking high power), however my longest use would probably be around 350yd mark...

Would you mind sharing some of the data you've collected in finding your OBT for diffrent powders/bullets/barrels ect. ?
Link Posted: 8/10/2011 2:34:47 PM EDT
I am also a big fan of the Optimal Charge Weight method, even though I am no expert reloader. I recommend it to anyone interested in the technical theories of reloading, and ballistics. My tip. Go progressive for pistols rounds. I really enjoy reloading, but doing 100 rounds of 45 auto on asingle stage was testing te limits of sanity for me, not to mention dulling to the point where I was worried about stupid mistakes. Yesterday I bought a lock n Load AP. Less than 2 hours to set up and set dies, then loaded 200 rounds in the next 45 mins. And I was going slow and measuring. Single stge is now for load development an anything to be shot out of a bolt gun

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Link Posted: 8/12/2011 4:27:13 PM EDT
[Last Edit: 8/12/2011 4:33:07 PM EDT by 308Sako]

Shot these today, XBR and 77 SMK, never saw such a low SD or velocity spread (See Oehler tape from 35P)... great powder! Distance 200 yards
Link Posted: 8/12/2011 4:44:10 PM EDT
I am planning to instrument a barrel with both strain gauges and acoustic sensors (microphones) in order to get hard confirmation of the above theories. I will update this document as that information becomes available. Any comments, questions, or suggestions can be directed to me at cdlong@speakeasy.net .


Years go by, but we never see report of the validation of the theory with the instrumented barrel described above. Until then, nice story bro.

Link Posted: 8/12/2011 6:27:03 PM EDT
I read your ideas and theory with great interest and I thank you for sharing them with us. Although parts of it I confess I do not completely understand as physics was never my forte (I am a biological scientist by training). Still the key parts of it I can understand and find intriguing and I hope things work out for you as I am currently struggling with many of the same questions.

I would whole heartily agree with you in terms of "change one thing at a time”, this is the key for successful research. If one would like to understand the effects of changing more than one thing, run each change in a specific group of rounds, that way you can test multiple theories at one sitting but still be able to isolate the effect of each variable.

I would like to ask you a few questions about your suggestions as it relates to case dimensions. First, how do you reproducibly measure a case in terms of location? The changes are I am sure small and location specific. For example some locations such as the start of the shoulder taper would not be hard, but other locations such as those two located in the middle of the case would I think be difficult.

Second, I realize that this data would help one understand "what changes are occurring to the brass during its usage” and how your dies are working the brass. Now case neck diameter, and shoulder location I can understand, but can you please tell me how you utilize the numbers you obtain for the other locations?

Link Posted: 8/12/2011 8:14:17 PM EDT
[Last Edit: 8/12/2011 8:16:49 PM EDT by 308Sako]
jlow,

Appreciate your questions and interest.

For the most part I use this data to verify the dies are correctly sizing the brass. If a case doesn't fit the chamber the bullet will not be aligned to the bore.

The mid case is simply eyeballed, and the taper being as slight as it is, its an easy spot.

The more important locus point to me is the location where the solid case head becomes the "gas vessel." It is very easy to see on a fired case, but can be located by measuring down into the case with a plastic stirrer if necessary on virgin brass.

The reason I suggest doing this is that not all dies are created equal, and I once had a Cooper 243 Ackley which the Redding dies were sizing the body of the case at the shoulder nearly .013" This made it near impossible to align a bullet to the bore. Concentric is what works. Yes, Redding made it right for me, they are great people.

Once you have seen the OCW actually pull your group together, you will never try an alternative method. It's like magic, but requires a precise rifle and good shooter to accomplish.

Good luck and good shooting.
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