.338 WinMag case head separation. Almost!

[ronterry]

Caught this after resizing from my latest range visit...
Gun: Browning A-Bolt /Boss SS Stalker.
Cartridge: .338 Winchester Magnum
Brass: Winchester
Number of reloads: 13-15
Bullet: HNY SP 225gr
Powder: IMR 4064 59.0grs (Light)
Primer: CCI-250
Notes: Annealed neck every three firings. Very normal load; 59-64grs IMR-4064 typical. Dies were RCBS X-dies. Number of rounds fired that day, 25 of 50, and 75% show signs but no splits after firing. NO signs in that area were present prior. In fact I sectioned a piece a few months ago on my mill to check for insipid head failure, but none where present.
Possible cause; shoulder setback more than normal? I will acquire a cartridge gage to further my investigations!


Pretty cool, I think! Hopefully my chamber isn't torched! Haven't checked that yet...
BTW: The split is 3/4 away around...

[hithard]

13-15 reloads per case, yes annealling the necks softens the brass there. but the rest of the case just becomes more brittle and fatigued. Now we all know that 12 is a good number to call it quits. Maybe even 10.

I highly doubt that your chamber was affected by this one time thing. but repeated offenses could have you looking for a new barrel, entire rifle, and maybe even a set of eye's and a hand or two.

Play it safe brother, we all need your vote in three yrs, and help keeping the NRA membership numbers up.

[ronterry]

That's exactly what I bought up with a couple of folks. Most call it quits on 6 with belted mags, but yes 10 sounds good to me with the X-Dies and keeping the loads modest and everything else being equal...

[ronterry]

Here's the one on the left, sectioned... These guys went from good straight to insipid and than some in one firing...

[Slow Elk 45/70]

Controlled test on brass endurance have been run on different brands of brass to see where it fails at with the 308 cal . This is information from Hand-loader Magazine.

Brass-Nosler--11 shots / Fail
Federal Military--11 shots / Fail
Hornady 12 shots / fail
Federal regular/plated 13 shots / fail
Winchester 14 shots / fail
Lapula 15 shots / fail
Remington 20 shots / fail
Remington plated 22 shots / fail
Norma 24 shots / fail

As You are aware there are a lot of variables, to many to list, chamber, pressure , boolit, primer, powder case stretch and on and on. This test started with new brass.

I have shot cases a lot more than this with cast loads and LOW pressures , but beware it can go South.

IMHO, I never go past 5/6 loadings with Magnum caliber brass. I have been there and done the case head separation blivet. It is no fun, didn't really hurt anything Luckily , lot of blow back from one of my Sako's , still not something I want to do again.

Just a little more information for the Loony Bin , use it or ignore it, it's just reference material.

Have Fun , Be Careful.

[ronterry]

Wow, very surprised of the Norma endurance! They must have some metallurgy secrets there?
I'm glad my 458 Lott are all Norma, cause I'm pushing about 10 on those suckers. All cast, and all medium warm pressures.
However my 458 Winmags, are necked up Winchester 338 from the same batch! Might pull em, and play it safe!

[runfiverun]

straight wall seems to fare better.
the softer the brass to begin with seems to take longer to harden.
wanted to ask, the strange crimp you got there.
how'd you get that? or what'd you make it with?

[ronterry]

That's made from a Lee Factory Crimp Die. I'm a rebel! I crimp em if they have the grove.
It's never affected my accuracy! But it sure keeps them from pushing out if I load up the box mag...

[303Guy]

ronterry
Something I notice in those pics is the absence of 'creap' marks on the two cases. I would be expecting to see progressively longer creap marks toward the case head. Is that usual?

[243winxb]

Great photos of a case head separation.