Years ago, as in 1973, I used a .375 BRNO with the flip-up peep and bead front sight to get into 3-position shooting. The load was a Lyman WW cast W/CG 272gr. bullet loaded with 23gr. of SR7625 (+ a tuft of dacron) and a CCI 200. That load would just hold the 1 1/2" 10 ring of the normal 3-position target when shot off the bench.