I recently bought a 270 Browning BAR. I dated the serial number to 1980 or 81. Anyone else been using these guns pretty regularly? It operates good, and I’ve looked for one for awhile, BUT it seems to only like Winchester deer season XP bullets. Is the new stuff like Hornady eld-x or sst to hot for that barrel? I can only get the xp’s to really group dime size groups at 100 yards, anything else is pretty much all over a 10” target.