ORIGINAL: ipscshooter
That's interesting. Do you know whether it is related to the rate at which the powder burns?
I guess I thought that the effect of Isaac Newton's law stating that "for every action, there is an equal and opposite reaction" meant that if you are pushing a 240 grain bullet at 1100 fps from two different loads, the recoil should be about the same regardless of the weight of the powder charge.
Part of it is impulse or acceleration in the barrel, but most of it is due to it actually becomes part of the load. So 50gr of powder adds that weight coming out of the barrel compared to 25gr. The powders weight coming out is not neglible and doesn't just disappear. Its still has mass, no matter if its a gas or solid. And that mass adds to the load coming out of the barrel muzzle.