I have a bit of a head scratcher here. My brother recently got a set of swagging dies at a gun show and has been happily swagging bullets. He shoots mainly .38 special and .357 magnum and has been happy with the bullets he's been producing and shooting. He made for me some hollow point bullets for my .45 ACP chambered guns using a .40 caliber core made from wheel weight lead. The resulting bullets weighed around 217 gr. Checking through my reloading manuals I settled on 3.0 gr of Bullseye for a powder charge. It would be a light load, but should certainly clear the barrel and hit the target. First one I chamber and fire didn't sound right or felt right. I immediately removed the magazine and ejected the unfired round that chambered. I look down the barrel and there's the dumb thing stuck and grinning at me.
I took it back home and managed to tap it out with a 3/8 dowel rod and a hammer. Looking at the bullet I notice that there are very few if any marks from the grooves of the bore on the bullet, and from the carbon marks it would appear that hot gasses had blown by. When I measure it I find that the bullet now measured .451 not the .452 that it was before.
Is it possible that the core didn't expand enough into the jacket, which when fired caused the jacket to crumple letting the gasses blow by and encouraging it to come to a screeching halt inside the barrel?