Bullet Weight vs. Recoil/Muzzle Rise

[Big Frank]

Powder weight plus bullet weight causes most of the recoil and the velocity doesn't matter as much, but since the bullet weighs so much more than the powder, I'm going to ignore the powder weight. If you double the bullet weight but the velocity stays the same, you double the energy and the recoil. If the bullet weight stays the same but the velocity doubles, you get 4 times the energy, because the energy increases as a square of the velocity, but the recoil is only 2 times as much, not 4 times as much. Lighter bullets always have less recoil than heavier bullets at the same muzzle energy. The gun may or may not recoil faster with lighter faster bullets, but it will always kick HARDER with slow heavy bullets of the same energy.

[Ocin]

From wikipedia: http://en.wikipedia.org/wiki/Recoil

Recoil is from the law of conservation of momentum. Energy is a quality of work that can be measured. When discussing recoil and energy it tends to be more understandable if one thinks of them separately.

The recoil of a firearm, both large and small, is a function of the law conservation of momentum and can be stated mathematically as mf·vf = mp·vp from Newton's third law.

The energy of a recoiling firearm can be stated mathematically as Et=0.5·m·v² from Newton's second law.

The following are base examples calculated through the Handloads.com free online calculator, and bullet and firearm data from respective reloading manuals (of medium/common loads) and manufacturer specs:

In a Glock 22 frame, using the empty weight of 1.43 lb (0.65 kg), the following was obtained:
9 mm Luger: Recoil Impulse of .78 ms; Recoil Velocity of 17.55 ft/s (5.3 m/s); Recoil Energy of 6.84 ft·lbf (9.3 J)
.357 SIG: Recoil Impulse of 1.06 ms; Recoil Velocity of 23.78 ft/s (7.2 m/s); Recoil Energy of 12.56 ft·lbf (17.0 J)
.40 S&W: Recoil Impulse of .88 ms; Recoil Velocity of 19.73 ft/s (6.0 m/s); Recoil Energy of 8.64 ft·lbf (11.7 J)
In a Smith and Wesson .44 Magnum with 7.5-inch barrel, with an empty weight of 3.125 lb (1.417 kg), the following was obtained:
.44 Remington Magnum: Recoil Impulse of 1.91 ms; Recoil Velocity of 19.69 ft/s (6.0 m/s); Recoil Energy of 18.81 ft·lbf (25.5 J)
In a Smith and Wesson 460 7.5-inch barrel, with an empty weight of 3.5 lb (1.6 kg), the following was obtained:
.460 S&W Magnum: Recoil Impulse of 3.14 ms; Recoil Velocity of 28.91 ft/s (8.8 m/s); Recoil Energy of 45.43 ft·lbf (61.6 J)
In a Smith and Wesson 500 4.5-inch barrel, with an empty weight of 3.5 lb (1.6 kg), the following was obtained:
.500 S&W Magnum: Recoil Impulse of 3.76 ms; Recoil Velocity of 34.63 ft/s (10.6 m/s); Recoil Energy of 65.17 ft·lbf (88.4 J)
In addition to the overall mass of the gun, reciprocating parts of the gun will effect how the shooter perceives recoil. While these parts are not part of the ejecta, and do not alter the overall momentum of the system, they do involve moving masses during the operation of firing. For example, gas operated shotguns are widely held to have a "softer" recoil than fixed breech or recoil operated guns. In a gas operated gun, the bolt is accelerated rearwards by propellant gases during firing, which results in a forward force on the body of the gun. This is countered by a rearward force as the bolt reaches the limit of travel and moves forwards, resulting in a zero sum, but to the shooter, the recoil has been spread out over a longer period of time, resulting in the "softer" feel.[

From The Physics of Everyday Stuff http://www.bsharp.org/physics/stuff/recoil.html

Secondary Recoil
There are actually two distinct recoils from a gun: the first, primary recoil, which I've described above, conserves momentum of the gun-bullet system. However, a larger secondary recoil comes slightly later, when the bullet leaves the muzzle: then the hot expanding gas behind the bullet shoots out of the muzzle, and the muzzle recoils further like a rocket. This is, again, conservation of momentum, but in this case is is the gas momentum out of the barrel that makes the secondary recoil. Gun manufacturers make baffles that reduce the flow of gas out of the muzzle to reduce secondary recoil. Primary recoil cannot be reduced, since it is simply associated with the forward momentum of the bullet.