I built two AR uppers this year, one in 450BM the other in 350L. Both have 16" bbls. I sighted them in at 50 yards simply because it was cold and snowing at the time and I didn't want to traipse 100 yards back and forth through deep snow. Both shot one into ragged hole at 50 yards.
The 450 has significant recoil out of a AR. More so than the Ruger Ranch I had shot earlier in the year. It was uncomfortable to shot. The 350 recoil is very mild, about the same as the 223 which is surprising. Was using Hornady 250 gr FTX factory ammo in the 450 and Federal 180 gr Power Shok in the 350.
I killed a doe opening day of the season with the 450 at 75 yards. One shot, broadside, DRT. Didn't even feel the shot recoil wise. I killed a second doe at the end of the second week with the 350. Front shoulder shot at about 65 yards DRT.