GTA
General Discussion To Gateway To Airguns => Back Room => : TCups July 18, 2009, 01:37:22 PM
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Well, I got the CZ-527 Varmint sighted in with Joe Cuz's Hawke Eclipse and had it shooting MOA 1-inch groups at 100 yards. But a funny thing happened when I ejected the case from the 4th round of this group.
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Looks like a problem with them there cartridges. Hope your chamber is still ok. Are those bullets made in China?
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What do you suppose caused that Tommy. Is there any indication of the brass being bad or thin wall?? That is strange.
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No, made in USA. Reloads. Black Hills .223 52 gr boat tail hollow points, moly coated. The split case, as it turns out, is not uncommon, and no, no damage to the rifle. The splits come from the brass having been fired in a chamber with the wrong headroom height, resulting in a stress on the cartridge and showing up as a stretch mark before the cartridge fails. Usually happens in full auto weapons, and these were probably reloaded military brass. The split will always occur above the taper in the base of the brass, so there is always enough of the butt of the brass left for a pressure seal. It did get my attention, but some research on the powder burner forums from some of the military and ex-military types resulted in a pretty much "ho hum" reaction. I checked the rest of the rounds and found a few more unfired with similar stretch marks. If I could find em, I would buy factory new 52 gr. BTHP's, but they are hard to come by these days. I did get one group from this same box of ammo that was a ragged 1-hole group just over 1/2 inch at 100 yards -- then left the target in the place at the mountains, so I can't photo it and brag about it.
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See above, Bob. See the radial stretch marks on either side of the split brass? I have to think it is more of an issue in a semi-auto or full auto. Bolt actions wouldn't be affected unless you happen to chamber the next round forcefully if only half the brass eject. In my case, both pieces of the brass ejected. Since I am saving my brass these days, in hopes that one day, small rifle primers will once again be available, I spotted the problem immediately, ejected the magazine, found both pieces of the brass, and cycled a couple of un-fired rounds. Then I fired one last shot (the 5th shot of the 5-round group) uneventfully. But I didn't shoot any more until I had thoroughly cleaned the rifle.
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It's a combination of things that do it. A head spacing issue may have indeed caused the brass to stretch. It is also from the brass being reloaded, overworked, and not annealed. The brass becomes brittle and will fail at the weakest point with the highest pressure. Bear in mind that if the was 5.56 mm Military brass, which is very likely, there are very subtle differences in the specs. between 5.56 mm Mil. brass and .223 Remington. Military brass is thicker walled, has a crimp applied both at the case neck and the primer pocket. I hate using Mil. spec. brass to reload for a .223 Rem.
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I would have already ordered myself the press and dies, but there are no small rifle primers to be had, so I guess I have to delay learning about hand loads and re-loading my own target rounds for a while.
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I've used the same Black Hills .223 'blue box' reloads for many years now in my Savage model 11. All 50 ga V-max, and it's all Lake City brass. Out of the 1000 rounds I have here, none look like that. All very well made and consistantly shoots groups in the 3/4 range at 100 yards.
But, ..... I stocked up with 300 rounds about four years ago. It's been tough to find more in recent months - I hope that's not what Black Hills is turning out these days.
I'd contact them directly if I were you.
http://www.black-hills.com/
I found that the ammo dealers were willing to replace what I bought, but at my cost to ship back to them. I started contacting the manufacturers instead and got better results. I've gotten much more replacement ammo from the manufacturere than I sent back to compensate me for the trouble. Maybe Black Hills will do the same for you ????
Paul.