This rifle is the Winchester Model 70 Bull Gun. The “bull gun” was the heaviest target rifle Winchester made at the time. Unlike the National Match and Heavy Target, the Bull Gun came with a factory 28 inch heavy barrel.
The receiver was made to accept the stripper clip that was the standard stripper used for the M1903 rifle. The stock was the heavy marksman walnut stock for use in target/ high power long range matches with a buttstock correctly made to be able to use optics or the Lyman adjustable match iron sights.
You can see the transitional style safety above.
Yes, the owner does have the scope block mounted on the barrel backwards.
The three target Model 70s can be confusing for people. The National Match used the same stock but a standard weight barrel like the same used on sporters. This was because weight limit rules for the matches at the time. The stock and a heavier barrel wouldn’t make the weight limit.
The Target Model used the same stock as the NM and a medium heavy barrel that is 24 inches. This same gun was later named the “heavy weight target”, the only difference being the front of the barrel on the HWT had two screw holes for sight blocks and the Target Model had a dovetail in the same place.
The Bull Gun had a heavier barrel of 28 inches.
Another great thing about the Model 70 ( the old ones anyway, not the FN made “model 70s”) is that the trigger is fully adjustable and it’s so simple even a glock owner could do it. I Can only guess FN changed this out to make their lawyers sleep easier at night. The trigger on a Model 70 is excellent and nearly fool proof.