Yes the 338 is a stock American wilderness rifle. I have only shot the included 250 lrx factory ammo in it but it did about 3/4-1 moa.
The 7wsm shot Hornady SST into cloverleaf groups. With a quick load development of 162 amax and h4831sc, it is about 1/2-3/4 moa. I only tried one powder, bullet, and seating depth. I really haven't shot it much in the last 7 or 8 years. Just checked the zero before hunting season in case I wanted to take it.
The only reason they are for sale is that I picked up some rifles in an estate sale to play with.