A number of years ago I inherited a bunch of Norma factory 10mm ammo dated from the 1980's when the 10mil was gaining ground.
I shot a few dozen rounds in my G20 and noticed strong variability in recoil pulse as well as a couple of split and bulged cases. Assuming higher than normal pressures due to welding I decided to pull bullets and save the cases/primers for reloading.
Initially I went with an inertia bullet puller but many of the bullets were so stuck I broke the first puller and then began developing tendinitis in my wrist working with the second from the continuous pounding to get the bullets to move. I switched to a home made collar and plyers setup in the rock chucker and this worked better but was amazed how stuck many of the bullets were. So far have had about a 20% rim failures via tearing off the cases due to the bullets being so stuck.
I've reloaded some of the factory pulled brass with the factory primer and most of the primers wouldn't fire either, so whatever caused the bullets to seize screwed up the primers as well.
Keep in mind this was Norma factory ammo purchased and stored in the original boxes in dry Colorado climate for over 30 years before coming to MT. My only theory for outside intervention would be if the ammo was stored on the floor of a garage during winter months where cold/warm temp. exchange might cause condensation to occur creeping into the cartridges.
So yeah, cold weld is thing as far as I'm concerned.
