View Full Version : Bi-metal 7.62 x

Sweet Shooter
August 19, 2012, 01:49 AM
The cheep stuff from the block countries—does it create cleaning problems? Excessive copper fouling? or gawd help us... steel fouling? I've fired about 60 rounds through this new 527 and I near used about 50 patches!!! Resorted to pulling strips of cloth through on a boot lace.


August 19, 2012, 04:06 AM
Hey Sweet,

Congrats on your CZ. I think a bolt x39mm chambered rifle is a dandy item and have the USA equivalent, a Ruger M77II.

My bolt rifle has not tasted any Com Bloc steel cased bi-metal ammo. For me, something about steel on steel /cases v. action, just doesn't riing true for a top end rifle, and so I reserve the cheap ammo for the AK and to a limited extent the Mini-30. Brass cased, domestic x39mm ammo is pretty common these days, more so than 15-20 yrs ago, and my bolt rifle gets the good stuff, and the Mini mostly too for that matter these days. I did shoot a good bit of Norinco and Wolf ammo throgh the Mini when I first got it, not so much anymore.

I have found that the com bloc stuff is pretty cruddy.

Regards bore/jacket fouling, you are aware that a patch with common cleaner, will NOT cut copper fouling? For that you need a bristle brush, and one of the copper fouling solvents so intended. The shooter who makes a box of shells last a season or two will not likely face a fouling problem soon, but a volume shooter will have to deal with jacket fouling . I've become a big fan of the foaming cleaners (intended for copper) and they have limited the amount I need to brush and JB (another mild abrasive cleaner) a bore.

I cannot say if a bi-metal slug fouls more or less than a standard copper jacket. If I see a lot of copper streaking at the muzzle, or accuracy starts to wane, I bare metal clean the rifle. I don't go this route every time, and some rifles need a few rounds to slick up. But heavy copper fouling will effect accuracy.

A lot depends on the rifle. Some bores are slicker than others. A Rem 700 ADL I have is a real shooter,...... for about 20 rds. Then the bore fouls and accuraccy deteriorates. I keep it cause its got some memories attached, and it is a shooter if kept bare metal clean.

A final word of warning. Be cautious of mixing odd lots of import ammo. Once upon a time I shot the Mini for 50-60 rds with what I thought was all non corrosive ammo. Steel cases, slug, it all looked the same. Unknown to me, a half dozen or so rounds of that lot was corrosive. I ran a patch through the bore, wiiped off the external surface and put the Mini away. A few days days later, I could not get the action open, the op rod had corroded onto the gas port! Some W-D and a few wacks with a leather mallet broke it loose, and it cleaned up OK. The bore was saved as I had given it a token cleaning before storeage. But it could have been bad.

You've got a dandy rifle there, take care of it and enjoy.

Sweet Shooter
August 19, 2012, 10:43 AM
Thanks bamaranger, that's all good to know. Yes I have been using a copper solvent. I start by using CR10 and brush with nylon, then patch it out. I then let some gunslick foam sit in there for a few hours... then patch out until clean patches come out. I then run some Butches oil... the red stuff. The good thing about that red stuff is that it turns color on the patch if there are any other chemicals still present. I just struck me that this new CZ took a bit longer than usual. Also maybe this just needs to be broken in a bit more. It shoots nice, about an inch and a half @100yrds on average (Iron Sights)... it's shot a couple of one inch groups too.

Anyone else have ideas/thoughts on the Bi metal jackets and excessive fouling?


Jim Watson
August 19, 2012, 11:24 AM
I near used about 50 patches!!! Resorted to pulling strips of cloth through on a boot lace.

I think you've answered your own question.
Try some commercial stuff and see if it fouls less.
But if you are getting 1 - 1.5" MOA with Iron Curtain stuff and iron sights, it seems worth the cleaning.

Do be careful about that bootlace thing. Hatcher's Notebook has horrible stories about hatcord and shirttail cleaning improvisations.