Question about .25WSSm

300winsniper

New member
I have a Winchester model 70, chambered in .25WSSM. It shoots great, very accurate with factory ammo and anchors Whitetails like a mack truck. BUT, it splits the case necks on almost evey shell fired, with a few exceptions. I have not started handloading for this caliber yet and was wondering why it splits factory ammo, and do I have need for concerne???
 
This usually only happens on old loaded ammunition that hasn't been properly annealed or with old cases since brass age hardens I believe. I'm talking 30 or 40 year old commercial stuff fired in factory chambers which generally have oversized chamber necks. If the necks are properly annealed they shouldn't split on firing for much longer than 30 or 40 years. Some REALLY old factory ammunition will show neck splits just from age, never having been fired.

You might want to contact Winchester and see what they have to say. Since the WSSM's haven't been out for that long they shouldn't be having any neck splits. Aside from ruining the cases and possibly burning the neck area of the chamber there's not much harm done. It's not a safety problem, but it shouldn't be happening with recently manufactured ammunition. Maybe the cases (necks and shoulders) weren't properly annealed before loading.
 
I have loaded and shot quite a few of the 25 WSSM. Never had a case issue.

I suspect your rifle chamber may not be correct. You should not be having this problem.
 
I have seen a similar split in 25-06 brass shot several times in a factory chamber and reloaded several times with a FL die when the brass was not annealed.

Usually it takes 4 plus cycles for this to happen. If the chamber is large and the brass is being moved more it could happen sooner. Brass gets brittle when it is worked.
 
I baught a case of PMC 7mm rem mag with 160 gr spire points.....about 30 years ago. Over half of them did the same thing in 4 different guns. I think I still have boxes of them laying around that missed the trash can....I'm not a very good shot!:D
 
This was brand new factory ammo (Box in the background) bought @ Gander Mtn. In November of 09?? Thanks for the help, I was just concerned there could be a possible safety issue, or it could damage the chamber.
 
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