High pressure ammo or loose chamber?

[Kroberts]

I think I put this in the correct section. But I'm curious whether this issue could be the factory ammo or the barrel. I've got a cz527 22 hornet that I could only find hornady varmint express ammo for. I finally ordered some PPU stuff from midway that doesn't have the problems I've had with the hornady. Initially I though I must have a very large chamber in tr rifle since when fired the hornady brass is swelled out in front of the case web, has flattened primers, and I could only get one or two loadings before the primer pockets wouldbt hold a primer, and about 1 in 10 would blow a pocket on factory firing. I've only fired about half a box of the ppu but it hasn't had any of those issues yet, though I havnt reloaded any of it yet to see how long it lasts. But the primers are nice and round, no blowouts so far, and no swollen cases. So do you think that lot of hornady is loaded too hot, is just too hot in my rifle. Or is my rifles chamber large causing issues?

I'm not complaining about hornady, I usually don't shoot factory ammo, but I love their billets and like their brass. I'm just curious if it's worth having my chamber cast, I'll probably do it anyway. The hornady ammo shoots better groups than the PPU does. After bedding the rifle it does 1moa vs the 2moa the ppu does I do need to make a chamber casting and check the bore diameter.

Thanks,
Kyle

 

[shortgrass]

Ya' check bore diameter. Check the bullet diameter of that factory ammo, too. While you're at it, check case capacity. Because it is European made, the CZ may have a .223 bore.

 

[RT2506]

I would suspect that it is just the Hornady ammo is too hot for your rifle. I have not shot any of the PPU 22 hornet ammo but I have shot some other calibers and it is not bug hole accurate. The cases have been really good though for reloading. I have loaded a lot of really accurate 7.5x55 Swiss and 7.62x54R ammo that have won vintage military rifle matches. I would do a load work up with the PPU cases and use a chrno to check your velocity. You can get the same bullet that is in the Hornady factory ammo to load up.

 

[barefooter56]

Kroberts,
Early lots of the Hornady varmint express ammo were very hot. Hence the staked in primer. Shortgrass made a good point too with the barrel diameter. Gunsmith can check that or call the factory.