Weatherby built 378s on S&L actions from 1955-1962. Serial number ranges were between 1721-3690 and S152-S455 according to Grits & Tom Gresham's book. Probably not that many were built however because not many have been identified by collectors. For instance, Weatherby also supposedly made 180 460s on Brevex actions between 1957-1962, however only 3 have been identified to my knowledge. Two types of S&L actions were used to make 378s, the earliest have a stack magazine, later models have a staggered magazine which reduces the potbelly appearance.

I'm looking at buying one of these, have found very little info on them other than Weatherby used these for a while before the Mark 5. Anyone have any experience w/ them? Any known problems? Thanks.

My first .378 was on the S&L action. Stacked magazine. I liked the pot belly looks, stock fit well, very accurate.

Barrel weight and overall weight were good as far as I was concerned.

I didn't like the rear locking bolt lugs. Got some stretching with full loads and really had to do a good resizing job to get them to chamber again. Used it intil the LH MkV showed up.

Regards,