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. Most authorities believe that 18,000 to 20,000 PSI is safe for all trap door actions that are in normal operating condition. These loads are operating at or below 18,000 PSI. 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. Shooting most types of smokeless powders at low pressures causes dirtier burning as well, but still, smokeless powders burning dirty at low pressures are about 95% cleaner than black powder and smokeless powders remain non-corrosive, unlike black powder, which is very corrosive. Remember, these loads feature smokeless, completely non-corrosive powder. An added benefit to these BPE loads is that they recoil very little relative to high pressure/high power 45-70 ammo. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.