I had a M70 FWT in .257. It was a long action, blocked to match "short" shells. I didn't like seating heavy bullets so deep so I set it up for 3" LOA loads, by changing the follower and magazine box to the same as for a 7x57, and had the throat lengthened. I loaded 120 gr. Noser partition bullets to 2800 fps using IMR 4350, and shot a couple of truckloads of deer and one bear with it. I had no more mysteries to discover with that rifle so I sold it to a no-good (former) brother in law. Wish I had it back.
Enjoy Yours!