Is annealing worth the effort?

[edgehit]

Let's say you just spent a lot of time creating wildcat cartridges that involved bumping the shoulder or changing neck diameter. Do you anneal the necks to relieve the theoretical work hardened stress? Or just shoot until the necks split and make some more?

[Bob Mc Alice]

Back when I was using a 7x57 I made many of my cases from both new and once fired .30-06 brass.This involved nothing more than running the 06 case up a standard FL Redding 7x57 die then trimming off about 5/16 inch of excess neck. This is a significant amount of shoulder set back and neck reduction. I chose not to anneal and just fire them as is until they failed. Due to things I wont discuss here my case life with the Ruger 77 was typically short at 6-8 firings. (OK, I was using a 7-08 neck die and the chamber was the standard .323 case neck diameter of 7x57's) At this point numerous small neck splits developed at the base of the neck at the shoulder junction.They developed quicker with reformed 06 brass than new 7x57 brass. Annealing may have gotten me more firings but I never bothered to try before that barrel wore out.

I do not think annealing right after this much re sizing would have been needed, the brass was fairly new and did not get stressed or work hardened that much. Maybe after a few fire and sizing cycles it may have got me more case life. I just shot them to failure and made more.

[RBriscoe]

Getting a consistent anneal is not all that easy without some sort of machine. You also have to avoid overdoing it or you can ruin the brass. I would do it before reforming the cases if I were going to do it. This eases the case forming process and the work hardening may even out some of the differences in the anneal.

That said, I agree with Bob that it is probably not necessary in most case reforming. If the chamber is large, as Bob says his 7x57 chamber is on the large side, unless you repeatedly anneal the brass the result is likely to be the same. You can test a few cases and see if it makes any difference at all in your chamber.

In my experience, it has not been that worthwhile either in terms of effort or result.

I don't know what wildcat you have in mind, but there really are not a great many of them that are worth the effort of much reforming as there are plenty of great cases ready to go or ones which require minimal reforming.

Tony Tello had a comment about wildcats and money that is very true and he has the experience to comment. Reinventing the wheel is tempting, but many have done so before and there are not that many which accomplish much.

Rick

[Snake]

Having avoided such tedious make-work lo these many years...I long ago was taught that such annealing is best suited to reformed brass and/or sloppy chambers where the cases really get worked. Since then and my discovery of precision chambers and necks my brass lasts longer than the barrels and out of sheer habit I get new ones with a new barrel on the "just because" theory. Ron Hoehn of Bench rest repute showed me a nifty machine that uses two torches (to properly cover the neck/shoulder) and rotates the cases in a timed fashion to water quench. Its all electronic and no quess work ....but its 5 bills without the Benz Matic torches. Now that gadget might get me to start annealing because its so cool

[RBriscoe]

Yea, Snake.

I think the machine Ron showed you is probably one that Ken Light makes. I have not used it, but am told that it works well and the results are consistent. Some of the long range shooters apparently use it to keep neck tension (and point of impact) the same as they use the brass.

It is still extra work in most instances with a well put together silhouette rifle.

Cheers,

Rick

[DanDeMan]

Ladies and Gents,

The below paragraph, in bold type, is part of an email sent to a buddy that's a top Palma marksman concerning an annealing test. Those of you that also shoot Palma and/or F-Class might find this post of interest. When shooting HP rifles from the 1,000-yd line, reduced MV variation is important. When shooting black powder cartridge rifles, reducing MV variation is an absolute must due to the bullet's long time-of-flight. At 500 meters an MV variation of 50 fps only causes about 1 inch of random vertical dispersion when shooting a 139 Scenar at 2,800 fps plus/minus 25 fps. From the 1,000-yd line a 308 Palma rifle will produce random vertical dispersion of about 5.7 inches for a typical match load that has plus/minus 25 fps MV extreme spread and MV = 3,000 fps. When a 45-90 is fired from the 1,000-yd line, the random vertical dispersion from a load that launches a 540-grain bullet to 1,300 fps plus/minus 25 fps is a whopping 18.7 inches. Below is part of the email sent to my buddy about the annealing test.

Yesterday's 223 Palma rifle testing went well; annealed vs non-annealed cases primed with F205M's, neck-turned cases, 1 thou neck-tension, Berger 90 LR under 28.5 grains of RL-17, mean MV = 3,040 fps. The annealed cases produced a 15-shot string that had an ES of 17 fps and SD of 5. That result made my day. The 15-shot string with non-annealed cases produced an ES of 29 fps and SD of 8; not bad, but the annealed cases did it for me. And, it should be added that the non-annealed cases had only been fired once before the test. Previous tests using a 284 match rifle showed that the more the cases are fired without annealing, the greater the MV variation becomes; more firings without annealing = more MV variation.

The neck-turned, Lapua cases tested had been fire-formed only. Thirty cases with the tightest weigh range were selected from the lot of 100 fire-formed cases and then divided into two groups of 15. One group of 15 was annealed and the other was not. All components were identical and the charges were weighted to within a kernel of powder; serious control of the first-order effect (charge weight) was the order of the day. A target with two aiming crosses was used for the test so that an annealed round could be fired in the left aiming point followed by a non-annealed round fired at the right aiming point so that barrel heating and fouling issues were spread across the test so as to not add convoluting variables that could skew the test results. Previous testing had shown that the more a batch of brass is fired without annealing, the larger the MV extreme spread and standard deviation.

Finally, case annealing is not very important for HP silhouette as can be seen from the above analysis. But, if you want to keep your brass in top shape and still launching bullets for many, many firings; proper annealing about every 5th firing will get your brass there. And, the sloppier the chamber neck, the faster the case necks will crack without annealing due to much more rapid work-hardening of the brass.

Come to think of it, a better HP vertical dispersion example would be a 7-08 launching the 168 SMK to 2,400 fps. That was the standard load for a number of shooters when I first started in HP silhouette. So, with an MV of 2,400 fps plus/minus 25 fps, the MV-variation-induced random vertical dispersion is about 1.56". That is still not that meaningful for off-hand shooting at 500 meters.

[Bob Mc Alice]

I recently retired 200 Winchester cases that had 25 firings on them. They were my mild CPT load fired in a SAMMI chamber (the Douglas match chambers) on the minimum side of all dimensions. They only needed trimming twice during their life. They only got neck sized, a light shoulder bump and fired. No annealing was ever done to them. Neck tension remained consistant to the end. They were scrapped due to imminant head failure signs, not any neck splitting. I think I got my monies worth out of them.

[Snake]

McAlice....you're experience mirrors mine. My chambers are all minimum dimension...ala pressure gun. My brass properly fire formed has gone well beyond 20 reloadings before retirement. I have never had incipient case head issues but suffice to say annealing wouldn't address that anyway. A good chamber is a must, and annealing is nice but usually unnecessary...I haven't split a neck except with my factory hunter gun! Annealing with factory chambers probably buys a little extra case life and uniform neck tension.
Actually ones time is better spent dry firing (which I am too distracted to do)..that improves scores and is real cheap.