Buffalo Bore offers 4570 ammunition that is externally identical to SAAMI spec 4570 ammo but internally it generates far more power and pressure. So their 4570 ammo will fit into any 4570 firearm but is not safe in every 4570 firearm. Its use should be limited to the following firearms All Marlin 1895 1895 Marlins are all model 336 actions chambered in 4570 iterations made since 1972 all Browning 1885 and 1886 copies Rossi Rio Grande New England Arms Handi Rifle TC Encore ALL falling block actions made of modern steel such as Ruger 1 and 3 Shiloh Christian and Persoli Sharps all Winchester 1886 iterations made since 1915 and all Siamese Mauser bolt actions.