Buffalo Bore loads their ammunition with the highest quality components available to maximize the performance of the ammunition. This ammunition is safe to use in all 357 Magnum chambered firearms with steel frames that are in proper working condition. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases. Owner of Buffalo Bore Tim Sundles on Buffalo Bore Heavy 357 Magnum Ammunition:For those wanting/needing a lead-free, HEAVY 357 Magnum load, generating full power plus, here it is. Below are real world velocities taken from my personal stock guns. The industry established use of long laboratory test barrels that give false high velocity readings is essentially misleading to the public who won't be firing the ammo from a laboratory test barrel in the real world, where it matters. 1.1947 fps Marlin mod 1894, 18 inch barrel2.1518 fps S&W mod 27, 5 inch barrel3.1519 fps S&W MT Gun, 4 inch barrel4.1436 fps S&W mod 66, 3 inch barrel5.1385 fps S&W mod 6...