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View Full Version : Factory Ammo brass showing symptoms of over pressure?



KnowledgeSeeker
03-22-2016, 01:36 PM
I bought a new scope for my Savage model 111 .270WIN and because it's no longer my all around rifle because I have acquired a Browning 7mm REM MAG for larger game IE. elk & moose so I decided to sight in the rifle for 130gr instead of 150gr which the previous scope was sighted for so that my .270WIN would become my dedicated deer rifle! So I grabbed a box of "Winchester Deer Season XP (Extreme Point)". And we set a target with a 1" grid out at 200yds to sight in the rifle (which only took 3 shots) we weren't really paying attention to the brass other than collecting it to be reloaded until we got back to buddies place and we noticed that the brass from the 130gr and I noticed that the brass has what looks like a "stretch ring" caused by headspace according to the hornady reloading manual has anybody else had these results with factory pressed ammunition? I have never had this happen with the 150gr same manufacturer!

kennymo
03-22-2016, 02:14 PM
Winchester

Hmmm....I may have located your problem....

Last couple times I've braved Winchester ammo it's been awful looking stuff. Gouges out of the bullets, ugly crimps, etc.... Others have mentioned coming across various QC issues....

The other possibility is your headspacing is a little out. Maybe measure a fired casing against the SAAMI numbers, could've been assembled on a Friday.... And check an unfired one to make sure the dimensions aren't considerably shorter than they should be...

blacksmithden
03-22-2016, 02:18 PM
If the gun wasn't doing it before, it shouldn't be doing it now....unless the physical dimensions of one case to another are different. I had a 300 win may that showed stress marks about 1/2" above the belt and would eventually crack there after 6 or so reloadings. It was a head space issue. I changed the barrel out and head spaced the new one and the problem disappeared immediately.

kennymo
03-22-2016, 03:00 PM
If the gun wasn't doing it before, it shouldn't be doing it now....unless the physical dimensions of one case to another are different. I had a 300 win may that showed stress marks about 1/2" above the belt and would eventually crack there after 6 or so reloadings. It was a head space issue. I changed the barrel out and head spaced the new one and the problem disappeared immediately.

Oops, I misread that as the new rifle was doing it...

Rory McCanuck
03-22-2016, 03:23 PM
A little confusing, but I think it was an older rifle that was fine with 150s, but is now showing signs with 130s.

Here's another opportunity for me to slag Winchester, so there's that.
Try it with another, any other brand of ammo, and see if it persists.
I doubt you'll see any problem signs.

Factory ammo can have problems.
I have a batch of almost 200 Federal cases that were factory ammo, all shot from the same gun.
Probably 20% of them, when I went to prime them, the primer just fell in.
They were relatively easy to sort out, as they all had an imprint from the ejector embossed on the head.

Poop happens.

KnowledgeSeeker
03-22-2016, 07:16 PM
To answer all the questions: the savage model 111 .270 is only 3yrs old and only had 4 boxes of 150gr put through it prior to attempting the switch to 130gr.

I did compare the dimensions of an unfired cartridge to the SAAMI specifications and the case is 2mm short and the all other dimensions are smaller
by 1mm

blacksmithden
03-22-2016, 08:57 PM
Here's what 300 win mag cases look like at various stages of impending failure due to a head spacing issue.

http://i207.photobucket.com/albums/bb93/blacksmithden/Shells004.jpg

http://i207.photobucket.com/albums/bb93/blacksmithden/Shells009.jpg

http://i207.photobucket.com/albums/bb93/blacksmithden/Shells008.jpg

Rory McCanuck
03-22-2016, 09:55 PM
Here's what 300 win mag cases look like at various stages of impending failure due to a head spacing issue.

http://i207.photobucket.com/albums/bb93/blacksmithden/Shells004.jpg

That is a beautiful representation, all in a pretty row.
Looks like you got all of your money's worth out of that last one ;D

blacksmithden
03-22-2016, 11:15 PM
I have a radiator hose remover hook thing that I've had for 20 years. It's just the right size to reach into the chamber of a 300 win mag bolt gun, dig the tip into the brass a bit, and pull out the broken case body without ever touching the gun. It saved me more than a few trips to the gunsmith with that particular rifle. It was a Steven's model 200 just in case anyone was curious.

I wish I'd had a better camera at the time. The light coloured line where things start to fatigue was a lot more visible in real life.

stevesummit
03-23-2016, 06:41 AM
The problem with belted cases . They initially headspace from the depth of the belt but the actual chamber could be slightly oversized and the brass it self could be held to minimum std spec . Which will leave the case no choice but to stretch to fill the gap . This will cause premature case failure even tho the head space shows to be correct .