Do heavier bullets mean more or less recoil?

[kraigwy]

A rather rare case since heavier bullets can rarely be driven to the same velocity as lighter bullets.

Not necessarly. My standard high power target load is a 168 SMK pushed out of my M1A at 2550 fps. In my 375 H&H I'm pushing a 270 grn bullet at 2550. Both rifles are near the same weight. The recoil is as differant as night and day. Its quite commen with mag v. non-magnums.

If one really wants to understand recoil, he needs to check out HATCHER'S NOTEBOOK, MG Julian S. Hatcher. on the Theory of Recoil. Gen. Hatcher goes in to way more detail that can be posted here.

BUT to answer you question, the heavier bullet will provide more recoil the the lighter bullet. It takes more energy to push a heavier object. The more energy to push the heavier object will also produce more energy to push the rifle back into the shooters shoulder.

 

[El Paso Joe]

It really 'all depends' as other posters have said. Momentum is always conserved so the momentum of the bullet exiting the barrel is equal to the momentum of the gun/shooter after the bullet leaves the barrel. The force is the integrated momentum through the change in velocity. Work is the force integrated through a distance. When it is all put together you get a second order differential equation that contains a first order term in time that is the "damping" or the response of the system that is being pushed back by the force - namely the gun/shooter and is dependent on the weight of the pistol (inertia), the grips/stock and how it is lined up and held. In practice, the equation is too hard to solve without a few assumptions...

The shooter pulls the trigger, the powder burns creating pressure, the bullet accelerates down the barrel, the gun/shooter accelerates backwards and by absorbing the 'equal and opposite' force and work is done. This work is the perceived recoil - mitigated by absorbers, recoil pads, grip, the shooter's body, and the like. Lots of variables. And it all depends.

In general, a fast light bullet will do its work on the gun/shooter quickly (it will be sharper) and a slow heavy bullet will do its work more slowly (but it does a bit more work). The work will depend on a lot of things - hence it all depends...

 

[brickeyee]

F=ma, High School Physics redux
Force (recoil) = mass multiplied by acceleration. If acceleration is kept constant, as roughly estimated by constant muzzle velocity, and the same firearm is used then force is dependent on mass. Therefore, recoil is greater with a larger mass bullet than a lesser mass bullet.

Major fail here.

Recoil is produced by conservation of momentum.
bullet mass * bullet velocity + powder mass * powder velocity = gun mass * gun velocity

The gun mass and velocity can then be used to compute recoil energy, 0.5 * gun mass * gun velocity^2.

THIS energy is then the recoil energy that must be dissipated.

The first real problem occurs in how the energy of recoil is dissipated.
If you had 30 ft-lbm of energy and it was absorbed over 1 foot, the force would be 30 pounds.
Absorb it over 6 inches and you get 60 pounds.
3 inches and you get 120 pounds.

The next issue is how that energy is actually absorbed.
Since most handguns have a barrel above the grip, some of the available energy appears as rotation and some as direct force backwards.
The guns mass and exact geometry of holding it comes into play in determining how the available energy causes movement.

It is obviously possible to drive a heavier bullet to the same velocity by changing calibers, or downloading the lighter bullet.

In the real world if you are using ammunition for self defense it is invariably loaded up to the highest velocity for the weight of bullet.

A heavier bullet WILL have alower velocity.

The 9mm drops from supersonic in the llighter weight bullets to subsonic at typical maximum weight bullets.

The .45 ACP is hard pressed to make even the lightest bullets supersonic, and the 230 gr never even gets close.

 

[DMZX]

I am not surprised that many here are well learned in the physics of motion.

Newton aside, I still tend to use 158 gr bullets in my small frame .357 Mag's, as perceived recoil is what is important when it comes to accurate and effective DA shooting.

Additionally, I have always had this bias - heavier=better.

 

[nate45]

F=ma, High School Physics redux
Force (recoil) = mass multiplied by acceleration. If acceleration is kept constant, as roughly estimated by constant muzzle velocity, and the same firearm is used then force is dependent on mass. Therefore, recoil is greater with a larger mass bullet than a lesser mass bullet.

Major fail here.

I was going to post that perhaps it its Newton's third law that applies here "To every action there is an equal and opposite reaction.", at least thats always the reason I give when I try to explain why a bullet fired from a personal weapon doesn't have the power to knock someone down. I'm going to have to research it now though, because I don't want fail, I want win.