today, i got a remington m14 in 30 rem that was made in 1925(91XXX). i have to field stripped and bore slugged it for cast boolits.
We found that out also. Bullet seating depth could even be a little bit short of O.A.L. as we found that if the rounds were a bit long, they would not be fed from the magazine.I've got a 141 myself. I bought it on a whim cause it came with several boxes of ammo. I've done some plinking with plated bullets. OAL length seems to be critical for function and the magazine can make a mess of cast bullets, if they're not hard cast. I have ran a few 168gr Eagan bullets through it. They worked ok, despite warnings I got from the fellows on the Remington Collector's website. I love the way it handles! I pulled some of the .307 bullets out of the Remington ammo to use for hunting rounds in my tight bored K31, but haven't gotten around to loading them yet.