I shot some 60gr sierra out of 300 Blackout accuracy wasnt good in AR maybe a single shot TC barrel would work and I earned dumb a$$ trip to gunsmith to get a stuck bolt open on a 300mag Browning Abolt playing with sabots.Not a developed wildcat, but shooting 55gr .22 cal bullets in sabots out of my 30-378WBY has to count for something lol