River Ridge;
Sorry, but I just cannot see enough detail to determine whether this is copper lump or not. I would not be overly concerned if it isn't though. I have over the years used conventional, dovetailed, shoe & mono-block barrels & I seem to recall perhaps ONE chopper lumped barrel. None ever came apart. The Pieper of course had the loose forearm lug & have had a few loose ribs, but those are entirely different issues.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra