Have one from a gun show.
It fired four rounds then jammed, something musta changed for it has yet to chamber another round since.
They don't lift the nose up high enough, bang nose into end of barrel below chamber of course bolt stops.
Ramp is clean.
Brand new magazine ($$$) behaves exactly the same.

it looks as if the barrel is somehow about 1/4 inch too far back...
were it forward it'd be flush with receiver and the ramp would push nose of bullet up a bit higher .

Anybody ever heard of a rifle barrel shifting rearward?
Why would anybody do that ?

Maybe i'll knock out the two barrel pins (part 3 on Numrich schematic) and see what's there on bottom side of barrel.

BTW Numrich had a few magazines - i think $58 . Looks like a good one, it's stamped "ERMA".

old jim