Hummm . . .
Dick, if you had trouble with BOTH drum and box mags, and since the drum was a Bridgeport rather than the lousy West Hurley 40 (I know, 39, really) rounder, I imagine the problem was with the bolt face or chamber throat.
Anyway, yours is gone now, so little use in this post mortem, I guess. Glad I've been able to keep mine. My only problems have been traceable to bad magazines, and briefly, to a broken ejector.
Best,
Johnny
MOLON LABE!