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Old 12-19-2013, 06:01 PM
montdoug montdoug is offline
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Location: Bozeman Montana
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Quote:
Originally Posted by GLShooter View Post
I had a "learning" experience last summer with a beautiful CZ 527 in 204. It decided to come unglued while I was PD shooting in northern Arizona. Froze the bolt, cracked the stock from behind the forward sling stud through the left side of the pistol grip. One LARGE crack!! Blew the extractor out. I caught a piece of metal (the extractor rivet) above the right eye in my eye brow area and several pieces of HV wood in the cheek and nose. Lots of blood ( scared my stepson REAL bad!!) but zero permanent damage.

The load was "published" max by a powder manufacturer. I had shot about 150 rounds of it with no problems. Velocities were not excessive for the bullet weight. The OAL seating was over max but the rifle had a large amount of room to the lands. (I've been loading over thirty years and can measure a throat.)

Anyway I sent the rifle out for a repair and picked up a 700 204 to shoot in the meantime. I just couldn't understand what happened to the CZ and it was driving me crazy. I had weighed all charges and had been using new brass. No powder or primer lot changes. Nothing unusual on the round fired previously.

I was getting set up to load for the new 700 and picked up a fired case from the CZ and was looking over the shoulder measurement with an RCBS Case Mic. It was over zero by 0.002 so the chamber was about right in sizing. I picked up a piece of unfired brass and it was right at zero. Then I picked up a piece of loaded ammo. (This was in NEW brass) It measured 15 thousandths (0.015) BELOW zero!! Needles to say I got some really cold chills.

I had about 150 loaded rounds that were with the previous load and checked all of them with a the Mic. about 40 % were undersized from 0.009 to 0.020 compared to new untouched brass. I had bought 500 pieces of brass for this rifle. 300 were one lot and 200 were another. I had rounded the necks, uniformed pockets and flash holes, chamfered the case mouths, primed and loaded these rounds. I HAD NOT resized the cases so the shoulders had not been touched.

I sent some case of all sets both unfired and fired along with some of the short shouldered loaded ammo to the manufacturer. They sent me a note back and told me they could find nothing wrong with the cases.

The ratio of one lot to the other was 2 to 3 or about 40%. The measured remaining rounds that were bad was about 40%. Now my old gunsmith told me there are no such things as coincidence in material/machine work so something must have been out of whack.

I threw away all 500 pieces of that brass and bought new. So far the new stuff has showed no shoulder movement on loading.

Just my experiences that may be germane to this discussion.

Greg

Very much so and I'm so glad you are alright!!! Something hits a guy right above the eye and it'd be pretty tough not to consider what might have happened had it been a little lower !!
This thread mentions so many things that are variables that sometimes I think we get a bit complacent and forget. In your case it seems it wasn't something a guy would even think about. Once again, glad you're ok.
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