I shoot 405 gr cast lead in mine, or the Hornady 300 gr HP. TRAPDOOR level loads only. The old shikari had a silver soldered barrel lug, and a cast frame. Ruger level loads may just turn it into a hand grenade. I love mine, I have killed 7 or 8 deer with it over the years. Shoots great, and doesn't pound your shoulder with the milder loads.