Ongoing argument

[Rocky Raab]

It's simple physics, really.

Recoil is simply the reaction to the action of accelerating the bullet and powder gas in one direction. Newton's law says there will be an equal and opposite reaction.

So, if you increase any of the three "thattaway" elements (more powder, more velocity or heavier bullet), you will get a proportional increase in the "thisaway" reaction (kick or recoil).

Powder has to be included because the weight of the powder (actually the weight of the gas produced plus the weight of any unburned powder) is also accelerated out the barrel. Use more of a slower powder and the recoil has to go up, as long as bullet and velocity stay the same.

In the original post, using an identical load with a lighter bullet will reduce the recoil - but not by a lot because you will also be increasing the velocity, which offsets the weight loss by a lot. Changing the velocity has the most effect because the formula squares the velocity.

Bullet weight, powder weight and velocity is why a .22LR hardly kicks at all, but a .458 Win Mag sure as heck does!