“please tell me with complete confidence that they will handle the feed rate of a full auto AR rather than the semi-automatics that they were made for without modification.”
I’ve seen it done with absolutely no modifications to the magazine, drum or standard.
L
The only drum I have first hand experience with was for a .22 semi, and squeezing rounds off too quickly made it jam up. Not that a .22 is a .223, I know. I would think the heat build up after the first 20-30 rounds would be significant.