Hope someone can shed some light for me.

I bought a 1917 M96 Carl Gustav 6.5 x 55 with a number 3 bore and, unfortunately, unmatching serial numbers. As it came completely slathered in Cosmoline I assume it's an arsenal job "franken-rifle" that was cobbled from parts for reserve use.

I ran 2 boxes of Winchester factory 140gr through it with pleasantly acceptable accuracy. However, after I neck-sized them to reload, I noticed cracks in the shoulders on approximately 25% of the cases.

Most of the ones that cracked had multiple cracks around the shoulder instead of a single split - some with as many as 4 separate cracks.

Case expansion does not appear to be excessive - I only neck-size 3/4 of the neck and the "step" is barely detectable. Any clues? Do you think this is a headspace issue (I don't), sloppy chamber tolerances (I hope not) or a defectively lot of extra-brittle brass (I hope so!)

Thanks

Measure some before and after cases in the shoulder neck areas- if there are not significant differences your hope of brittle brass might be correct. I would try another brand of ammo also.

Kettled,

There seems to be several reports of Winchester ammo brass that cracks at the neck.

I had some 06 ammo that cracked/spit at the neck , so I couldnt use it for reloading. Sent the box of brass back to winchester and they sent me a 50 piece bag of new unprimed brass.

I ve seen several post of the same problem with winchester ammo.

So It isnt your rifle ,its bad winchester brass. not anneled proberly or basisly crappy quality!

Maybe winchester figures most people that buy loaded ammo are not reloaders so they are selling ammo with junk brass that cracks. Only reloaders would know. Most people just leave the spent brass on the ground ?

Multiple cracks ? They didn't anneal the cases as they should have. Send them back and get replacements.

Hello,
You mention that you are neck sizing, not full length sizing and wondering if in some manner you are pushing back the case shoulder more than needed?? Do you know the chamber/headspace dimensions as determined by a Stoney Point or Moes gauge?? Beg, borrow, buy one of these guauges, Stoney Point proabably more likely, easier to buy, and then you can actually determine a numerical value to your chamber and resize your brass correctly to closely match the dimension of your rifles chamber. Frankly, I do not know how anyone can reload without one of these gauges to determine how you resize your brass. If you are only going to neck size, not a problem, but I would re think that approach. The rifle you have is not a bench/match rifle w/ a precise chamber and would want to resize the brass as much as possible to fit my particular chamber in order to prevent unnecessary expansion of the case when fired. As mentioned, some faulty brass does show up on the market, but that is not likely the case, could be, but usually something else-rifles chamber, or the person pulling the lever on the press. Have had both happen to me!!

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dsiteman

I would say you got a bad batch of brass, it happens when the big lots they process them in. go back to what works for you. Buy some new brass, and if it continues you do have a problem. vangunsmith