New brass life test: annealing

[CountryBoy19]

First of all, thank you for your service to God and Country. Your efforts are what allows us to enjoy these freedoms, including the right to own and bear arms. Take care of things at home before you worry about any of this stuff. What the two of you have already done speaks volumes about the benefits of neck-sizing;

Just so I don't get credit I don't deserve. I'm not armed forces and I wasn't doing the job that our armed forces are doing over there. The true thanks goes to them. The crap they deal with over there is a real eye-opener and if you ever get the chance to experience it (the lives they lead abroad) first-hand it will totally change your perspective on things. I was in a support role over there and I wasn't doing patrols etc so I was much safer than they were.

I'm not sure annealing will make that much of a difference. It's not like I really "need" to get more than 50 or 100 firings from each piece of brass.

That is pretty much my conclusion as well. Not too concerned about annealing for brass life anymore on the common calibers. If I anneal for anything it will be consistency in long range shooting or for wildcats that have a tendency of cracking necks. My dad has a 219 zipper that cracks necks bad. I think annealing could really help that problem.

 

[CountryBoy19]

BTT to make it easier for Shibumiseeker to find this. We completed the testing yesterday and overall results will be posted by Shibumiseeker.

A little teaser on what we saw on annealed vs. non-annealed neck-size-only brass:
It appears that annealing slightly increases the number of loads before cracks appear, but after a crack appears it propagates to failure much faster if the brass is annealed.

I think it is safe to say that after the tests Shibumiseeker and I both had the same conclusion, "We won't be annealing any brass for the sole purpose of increasing case life" The small increase before cracks appear isn't worth the effort.

Future testing that I think will also be valuable is wildcats and/or home-formed cases. IE, forming your own .300 BLK brass from 5.56 brass. Shibumiseeker mentioned he is having problems with his home-formed .300 BLK brass cracking in the shoulder area. The shoulder area on home-formed .300 BLK is just below the zone where annealing was done after case-forming at the factory so this may be a perfect candidate for annealing.

 

[coyotehunter4]

Great thread! I just picked up a 257 Ackley Improved and was contemplating annealing the brass after fire forming. I have not had any problems with cracking yet so I don't think it is necessary.

 

[shibumiseeker]

I was at IDHS all day for a training meeting so I'll get the writeup done in the morning, but it was interesting results!

 

[shibumiseeker]

Ok, so the final wrap up is:

Neck sizing with annealing every 5 loadings:

After firing 22, 56, and 79 brass was full-length resized as some of them were getting difficult to chamber without more force than we thought appropriate.

We considered brass to be dead after a neck split grew enough to make the brass not hold a bullet under moderate force (not full weight press against the table, but maybe half)

Brass was trimmed after firing 79 and 105. They had grown the most by 79, .002-.004 (estimated) and by 105 we were only shaving off .001-.002, but the mouth had developed a wavy edge, we postulate was due to the neck collet of the neck sizing die.

Failure 1, a small (2-3mm) crack was noticed middle of the neck at firing 60, started growing after 62 and had reached the mouth by 64 and we declared it dead at 65.

Failure 2, a precursor crack (on the surface but not on the inside) was noticed at 62, developed into a full thickness crack after firing 76, and was dead by 84.

Failure 3, small crack mid-neck after 120, reached the mouth by 123 and was dead after 124.

Failure 4, small crack mid neck at 123, dead after 124.

Failure 5, small crack mid neck after 130, reached the case mouth after 134, dead after 135.

Conclusions for this batch: For the small statistical sample size the data suggests but does not conclude that for neck sizing the annealing process did not increase case life and decreased it slightly over the control, but a larger statistical sample would be needed to be definitive. What was definitely noted was that the annealing process dramatically decreased the interval between when the first indications of impending failure were noted and when the case finally failed with the longest interval being 8 firings and the shortest being 1 for an average of 4.6 firings. For the control group, the longest was 43 firings and the shortest 13 firings for an average of 21.2 firings.

We had me do all of the reloading to keep the process as consistent as possible, and I noticed a definite change in the feel of the neck sizing after each annealing, which would mostly go away by the first firing and be completely gone by the second which suggests that if one is annealing for consistent neck tension then it needs to be done every firing, something that precision reloaders already know, but is always good to be backed up by more empirical data.


Overall conclusions (with this load, this bullet, and this rifle):

Full length resizing dramatically shortens case life (no surprise there). The annealing process makes more difference here with regard to reducing case life.

FL Sized-Not Annealed Average Case Life: 16.8 firings.
FL Sized-With Annealing every 5 shots, Average Case Life: 13.2

Neck Sized- Not Annealed Average Case life: 108.4
Neck Sized- Annealed every 5 firings. Average Case life: 106.5

Thus answering my original question: does annealing extend case life. I am satisfied that the data concludes that it does not. There are good reasons for annealing, but extending case life is not one of them.

Without sitting down and adding each one up I estimate I burned about 10lbs of powder, and 1500 primers/bullets (at least). I had been tracking the primer use by keeping the empty boxes to get the number but since the experiment took 23 months to complete I lost track of them, but the estimated component cost was about $600, which I am glad I did not have to outlay all at once. I had fun with the experiment and CountryBoy19 and I got to know each other a little better and found we've got pretty similar approaches to experiments and data and preference for empirical evidence over unsupported assertions, he was a good lab partner for this run, even if we both were too busy to be able to easily match schedules.

 

[shibumiseeker]

The last five cases.

 

[LarryC]

Great information, thanks for posting this! The only issue I (my son and I) have is that the annealing may be more advantageous when firing the reloads from various firearms. IE: We reload for all our firearms, in .308 we have a Winchester lever action, a LR-308 and a Saiga .308. We are currently determining if we have to full length size to use in all the rifles. We actually don't shoot the Winchester much so if it does require FL sizing after firing in one of the other rifles we my just Isolate the ammo for that gun. Hopefully the Saiga and LR will not require a full length sizing. If we do have to FL resizing to sami spec. annealing may be needed for increased life of the brass.

 

[shibumiseeker]

Great information, thanks for posting this! The only issue I (my son and I) have is that the annealing may be more advantageous when firing the reloads from various firearms. IE: We reload for all our firearms, in .308 we have a Winchester lever action, a LR-308 and a Saiga .308. We are currently determining if we have to full length size to use in all the rifles. We actually don't shoot the Winchester much so if it does require FL sizing after firing in one of the other rifles we my just Isolate the ammo for that gun. Hopefully the Saiga and LR will not require a full length sizing. If we do have to FL resizing to sami spec. annealing may be needed for increased life of the brass.

If you look at the conclusions, annealing significantly decreased brass life for full length sizing, moreso than for neck sizing alone, which was exactly the question we hoped to answer.

Regardless, neck sizing should only be used for brass used in non semi-auto guns, and only among different guns if the chamber size is very close.

FL resize for all ammo that may be used in different guns as that avoids problems.

 

[Broom_jm]

It seems abundantly clear that neck-sizing has tremendous benefits, while annealing may be of little or no value. It's interesting that it actually seems to reduce case life, if combined with FL resizing. That surprised me.

 

[shibumiseeker]

It seems abundantly clear that neck-sizing has tremendous benefits, while annealing may be of little or no value. It's interesting that it actually seems to reduce case life, if combined with FL resizing. That surprised me.

I think annealing for consistent neck tension is still a very valid reason to do it, but it will need to be done every loading (as I know many precision loaders already know). But for years I'd heard people say "it will make the brass last longer" but no one could ever point to data supporting that. Now we have data that disproves that.

 

[LarryC]

If you look at the conclusions, annealing significantly decreased brass life for full length sizing, moreso than for neck sizing alone, which was exactly the question we hoped to answer.

Regardless, neck sizing should only be used for brass used in non semi-auto guns, and only among different guns if the chamber size is very close. FL resize for all ammo that may be used in different guns as that avoids problems.

That may be true, I'm not certain that would be true if you are fire-forming the brass to different dimensions in multiple weapons then forming it to sami specs. The conclusions reached were limited to one firearm and therefore all forming caused the brass to move the same amount. You are most likely right, the fire-forming probably won't make any difference in the annealed results - hope we can just neck form - but doubtful as 2 of our .308 firearms are semi-auto and the other lever action (which is somewhat of a wildcard compared to a bolt action). Do a lot of shooting in 30-06 too, have a Garand, 1903-A3, and US Enfield - planning on getting a couple more Garand's this spring from CMP.

 

[shibumiseeker]

That may be true, I'm not certain that would be true if you are fire-forming the brass to different dimensions in multiple weapons then forming it to sami specs.

There's conjecture, then there's data. I prefer data.

But I'll throw out some conjecture: The primary failure mode for the FL resizing for both annealed and non annealed was incipient case separation which is a function of the sizing process and is only made worse by the action of a semiauto working the brass. Softer brass can flow more, so even though the case separation is in the area not affected by annealing, the shoulder and neck will allow the brass to stretch more in annealed brass during firing and extraction, thus causing more movement during the FL sizing process.

Keep in mind, we only annealed the FL sized brass twice (annealing every 5 shots) before all failed and that alone caused an almost 20% decrease in case life over the control group. Had we annealed after each firing that data suggests that case life would decrease further.

Regardless, since I am an empiricist, my next brass life test is going to be on 300BLK brass which I have not been annealing before forming from 5.56 brass, so I am planning on doing two tests there: one to see the difference in case life between brass that has been annealed before initial forming the control group, AND one to see how the brass life compares when the cases are annealed after each firing. Which should provide more definitive data than you or I conjecturing. Because people conjecturing can argue all day long and not really prove anything.

 

[shibumiseeker]

Bumping this thread and adding a pic of the telltale ring that develops for full length sized brass.