Great posting. I think what he was talking about is the jet effect of the gasses leaving the barrel. A bullet leaving under high gas pressure will produce more of a jet effect than a bullet leaving under lower gas pressure, even if both bullets are moving at the same speed, same weight. That is why a brake or compensator is more affective for rounds like the .38 Super than they are for the .45 ACP. As the gas leaves the barrel behind the bullet, the muzzle acts like the exhaust of the jet engine, pushing the handgun rearward. The recoil effect of the acceleration of the bullet cannot be countered by a brake, but the jet effect can be manipulated (redirected) by the brake and reduce that part of the recoil. Also to consider in recoil is the amount of powder needed. Bullet weight, powder charge weight, gun weight, all affect the recoil acceleration in ft-lbs of recoil energy. Since the .45 Colt is larger than the .44 Magnum, it will move a bullet of the same weight at lower pressures, but it will take a larger charge of powder to do so. Since the differences are so slight, they kind of cancel out each other (lower pressure and more powder)and you would be hard pressed to tell the difference between the two(the .45 Colt produces only 1 ft-lb of recoil more than the .44 mag, but uses 1.5 gr. more powder to do so, 300 gr. bullet at 1300 fps), but if you move up to a different caliber, like the 416 Remington with it's 400 gr. bullet at 2400 fps, and the .416 Rigby, equal weight, equal velocity, it take a lot more powder to move the Rigby's bullet, but it does so at less pressure. In guns of equal weight, the Rigby will give more recoil (68 ft-lbs Rigby vs 60 ft-lbs Rem) because it uses 20 more grains of powder to do the same thing as the Remington, but a brake is more effective in reducing recoil on the Remington since it is opperating at near twice the PSI of the Rigby. What is a maximum load for the Remington is merely a starting load for the Rigby.
Clar as mud, I thought so. I have a headache now; got any aspirin?