Getting Neck Splits on new 7.62 NATO

[Dollar Bill]

I'm thinking that concentrating the flame more on the mid neck with the traditional tip would probably give you best results. (I tend to do things by muscle memory now, so I didn't really notice that when I aneal/took the picture above, I hold the case at a natural angle to the flame that causes that flame to fully encase the neck region.)

I've annealed more than a few cases over the years and found that the method you described is the way to go. There's no point to annealing the shoulder. Annealing the neck does two things for you. First, the point of this post, is to alleviate neck splitting. The other purpose is to control and equalize neck tension, which enhances accuracy. With some practice, annealing is easily accomplished using a propane torch, shell holder/cup in a drill, done in a dark room. As soon as you see the neck start to turn a dark reddish color, you're good. But for match cases, templac is the way to go. As previously stated, you get better consistancy with the resulting improvement in accuracy. Starline brass I anneal from the start, as their brass provides too much neck tension for cast bullets (which I shoot alot of).

[Danny]

Here is an alternate, unwanted explanation:

Your pull down brass may have been weakened by the gasses released by deteriorating powder.

There is a tremendous amount of denial on this, but powder deteriorates.

When double based powders go bad they release nitric acid gas. This gas will cause corrosion and will attack brass. I don’t know how, but it does.

I had surplus 4895 go bad in the case and cause green corrosion on the base of bullets and case neck cracking. Case necks are more highly stressed than the other sections of the case, and it is thin. My guess that is why the necks crack.

I have been told the Army scrapped ammunition based on clock time. It is 20 years for double based powders and 45 years for single based. Your brass may have been laying loaded far longer than it was supposed to, before it was scrapped. There is the chance the powder in the cases was just starting to go bad.

The cases with split necks, toss them. Cases without split necks, anneal the stuff, do the rain dance, cast dark magic spells; if it helps, it is worth doing.

If it does not help: you are hosed.

Ok,
This is an old topic which I thought I had solved, but this idea came to my mind after a mishap at the National Matches. I was shooting the long range phase with my M1A and came up witn an unexplained miss. Later, upon sorting my brass, the same brass I had to anneal based on these postings, I noticed a split case, which upon further inspection, revealed some nearly invisible cracking about 180 degrees around the case from the split, almost like a "spiderweb crack", not a simple crack (and not what you'd call a split). These are cracks and splits in the body area. Annealing never completely solved the problem of the neck splits I had, but it got it down to next to nothing. I'd get maybe a split or two since then, but the majority of them were reduced to what I'd call "nicks" in the case mouth (which were few and far between), which would have become splits if I had not annealed. I wonder if the brass hadn't gotten damaged as above, causing the body splits and cracking? In any case, I'm going to discontinue use of that lot of brass. I only bought it because I needed somehting, and at that time, getting any brass was iffy. Normally I use commercial, one lot for my long range loads. I fired maybe 3/4 of that 1000 piece brass lot. I'lll try to take and post some pictures later. Hopefully, I remember how to post them.

Danny