Buffalo Bore Ammunition 25A20 Heavy Low Flash 357 Sig 125Gr Handgun Ammo - 20 Rounds - Buffalo Bore produces two full power 357 Sig. loads. These loads are full power 357 Sig, not watered down stuff. The 357 Sig was designed to blast a 125-grain bullet at 1425 FPS out of a four inch carry gun barrel. These loads use flash suppressed powder for a huge tactical advantage.