Hatari

Feeding cartridges in the barrel ( a problem wiht the .500 Jefferey, I think due to rebaded rim,)"

Original 500 Jeffries did not have this problem (from people who owned them)
I have an exact copy from an original 500 Jeffrey and it doesn't have any problem.
I know of numerous custom built 500 Jeffrey's that also don't have any problem feeding
(both Mauser 98's and Brno's (CZ) 602's and 550's).

I think the "problem" feeding 500 J cartridges from the magazines is because the gunsmith's
of custom rifles didn't take care to see how it was done and let the gun out without testing it.

That is not to say that having a rebated rim is good, just don't blame the cartridge.

500 Nitro