Buffalo Bore low pressure “Black Powder Equivalent” 45-70 loads are safe to use in “Trap Door” actions, assuming the action is in normal operating condition. Original (1873) 45-70 Govt. ammo was released to the military, in the military rifle of the day, which was the Springfield model 1873. SAAMI has set 45-70 pressure levels at 28,000 PSI, which is potentially enough pressure to damage trap door actions, depending on the pressure curve of the ammo.

We know from history that 45-70 loads of this power level literally pounded 2,000+ lb. bison. As bullet diameter increases, velocity and bullet expansion is less important in causing the bullet to be lethal to large animals, and a 46 caliber, (.458 inch) non-expanding bullet is very big, relatively, so this low pressure/low velocity 45-70 ammo is very lethal to big critters.

Ammunition 45-70 Government 405 Grain