A member asks about varnished Wolf ammo and it's chamber jamming problems. I wonder about the actual size of the bullet. I've been told that Eastern block and Chinese  7.62x39 is not a good choice for American made rifles chambered for this round because it's bullet diameter is larger. Anybody know the straight of it. And what exactly happens to a bore when a slightly oversize bullet is forced thru it? Thanks, Mikke

In regards to the Wolf 223 ammo, the bullet (tip) is still .223, not oversized.

The chamber sidewalls to case size is what comes into play regarding the ammo. The Wolf case is still in spec, but if used in a tight chamber, the case is expanded on ignition blowout, but the lacquer coating will grab the chamber walls with more friction than a brass case.  To even further complicate the situation, the powderized lacquer fouling leads to the case having even more friction to over come in regards to a clean release from the chamber side walls on ejection.
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As for bullet (tip) size, the only place that an oversize bullet comes into play is in regards to the 7.62x39 Mini-14.  The barrels on the Mini 14 rifles are tapered from the chamber to the muzzle to allow the rifle to shoot both .308 and .311 bullets (tips).  The barrel starts off with the .311 bore, than tapers down to stabilize a .308 size bullet.  This allows both .311 and .308 bullets to be used when reloading for the rifle.  Also, this explains why some American 7.62x39 ammo is not as accurate as import ammo in regards to the AK-47; the .308 bullet size is used in the USA factory loadings are too small for the bore of the AK-47.