.338 Win Mag Brass Splitting

[Poygan]

I decided to expend some .338 reloads prior to putting the M70 up for sale. Fired three rounds and all three had necks splits, one the length of the neck and two with smaller splits. The brass was two super-x and one super speed; probably only reloaded once but only twice at the most. Hornady 250 grainers with 65 grains of IMR4350, CCI primers. Found one empty fired in 1983 when I reloaded these and it looked normal, no splits at all.

Most of my reloading has been with pistol calibers but I do load .270, .223 and 7.62 X 39 and have never experienced such consistent failures. Any ideas as to what is happening here? Could case age be a factor?

[454PB]

I've seen this happen in ammo that has sat around loaded for many years, seems the brass gets brittle and splits when fired.

[BruceB]

Poygan sir;

Having used a great deal of "Winchester" rifle brass over the decades with satisfaction, including those stamped Super-X, Super-Speed, WRA, WCC and so on, I was surprised to encounter a problem similar to yours with recent-manufacture .338 Winchester Magnum -caliber brass ONLY.

My WW .338 brass was splitting mostly in the shoulder area, with some splits occasionally developing in the case necks. The neck splits usually did not go all the way to the mouth, but were visible on the side of the neck. The shoulder splits ran lengthwise, just like the ones in the neck area. The splits occurred very early in the case's 'life', often after only one or two loadings. All my brass was bought new/unloaded/unfired.

All cases showing splits were discarded, of course, but since I don't keep as good control over brass "lots" as I should, I just had to keep a close watch until cases with splitting tendencies worked their way out of my system. I found that the cases usually didn't split in the loading process, but rather in being fired.

Newer WW .338 brass, bought in the last year or so, has not given me any trouble. Perhaps they had one big production lot with out-of-spec annealing or something similar, although your problems with earlier-headstamped cases make me wonder about that. I've never encountered this situation with Winchester brass in any other caliber.

[Poygan]

BruceB,

The shoulder splits were more common than the neck split so your experiences parallel mine. Now I'm glad I resisted the temptation to get a mould for it.