Powder type and charge vs felt recoil

[Doom2]

Recoil is a result of accelerating the bullet and and /powder gas up the bore of the rifle. You can thing of it simple as F=ma where m is the mass of the bullet and the powder at any point in the barrel. That force is exerted on the rifle as well. You can go to SAAMI and find the recoil velocity and energy formula. The rate at which that force is changing is what we perceive as a push or a punch. A punch is what we feel when the acceleration is changing rapidly and a push is a more gradual rate of change in the acceleration. In the physics world this rate of change of acceleration is called "jerk" and no I'm not making that up. Because faster powders generate pressure faster the bullet accelerates faster and for a given bullet will make the recoil feel sharper than a slower powder which builds pressure slower and creates more of a push when giving the same velocity. It is also not unusual for a rifle cartridge to have the powder contribute 30 to 40% of the velocity that creates the recoil energy.

 

[Hugnot]

All of them as well as reloading manuals, and what SAAMI has in calculating recoil (felt/perceived) are simulations or references and YMMV. If you want an actual measurement, you need a means to measure the actual force/energy generated by a load combination. Ultimate Reloader had a similar set-up when they measure muzzle brake reduction effectiveness. His set-up was not cheap. He also wriote the software program to show what he was trying to measure.

A savvy QL or GRT end-user might be able to do a more informative simulation.

In your example in #1, whichever load combination has the higher energy would probably generate more felt/perceived recoil.

Good luck!

ADDED: This is with 190 Berger VLD out of my .30 Gibbs; same COAL/CBTO.

61g H4831SC, MV=2599 FPS/E=2850 FT-LBS

56g RL-17, MV=2778 FPS/E=3256 FT-LBS

Rifle weight matters!!!

Assuming this is an ordinary hunting rifle, like a rechambered/re-barreled .30-06 that weighs 8.3 pounds with a nice 4-15X42 scope intended for carry in the woods for shooting deers & elks. Possibly 22-inch #2 barrel, aluminum rings, and a nice 1 inch thick recoil pad.

Or a heavier .30 Gibbs having a 24-inch, #4 barrel weighing 9.8 pounds. Possibly bigger scope & whatever attached to rifle.

Adding 45 fps, for the extra 2 inches of barrel length.

The laws of established science are inexorable. Newton, the real olde physics guy was probably energized to get into this stuff when the falling apple hit him.

The two screen shots are identical except:
The top SS shows the method for calculating rifle velocity (by momentum, P*V, vector) as the rifle is pushed back into the shooter body, like Wt1*V1 + Wt2*V2 / Wt3, Wt3 is weight of rifle in grains, like lbs * 7000 - keeping all units the same. The rifle velocity is calculated using the established physics laws of momentum, P = M * V, a vector having direction and velocity.

The bottom SS shows the method for calculating rifle kinetic energy (applied energy) as the rifle hits the shooters body,like R= 1/2 M*V^2. The velocity of the rifle has been determined, the standard mass calculation is made by division of acceleration of gravity converting pounds into slugs then the kinetic energy of recoil is determined.

Of all the recoil info stuff I looked at I liked the Robinette info best. In his presentation a photo was shown as powder gas out-accelerated the bullet. Robinette provided 1.7 times bullet velocity to get powder gas velocity. I used the 1.7 in my calcuations.

The momentum would be less as powder weight decreases. The powder gas velocity increase over bullet velocity provides an appreciation of various muzzle brakes.

I had a Vais brake on my .375 H&H and at one time when I fired it other nearby shooters thought I had a KABOOM! Muzzle brakes are noisy but work as they reduce the jet effect of raging powder gas acceleration.

 

[Brathany]

Rifle weight matters!!!

Assuming this is an ordinary hunting rifle, like a rechambered/re-barreled .30-06 that weighs 8.3 pounds with a nice 4-15X42 scope intended for carry in the woods for shooting deers & elks. Possibly 22-inch #2 barrel, aluminum rings, and a nice 1 inch thick recoil pad.

Or a heavier .30 Gibbs having a 24-inch, #4 barrel weighing 9.8 pounds. Possibly bigger scope & whatever attached to rifle.

Adding 45 fps, for the extra 2 inches of barrel length.

The laws of established science are inexorable. Newton, the real olde physics guy was probably energized to get into this stuff when the falling apple hit him.


View attachment 610479
View attachment 610475

The two screen shots are identical except:
The top SS shows the method for calculating rifle velocity (by momentum, P*V, vector) as the rifle is pushed back into the shooter body, like Wt1*V1 + Wt2*V2 / Wt3, Wt3 is weight of rifle in grains, like lbs * 7000 - keeping all units the same. The rifle velocity is calculated using the established physics laws of momentum, P = M * V, a vector having direction and velocity.

The bottom SS shows the method for calculating rifle kinetic energy (applied energy) as the rifle hits the shooters body,like R= 1/2 M*V^2. The velocity of the rifle has been determined, the standard mass calculation is made by division of acceleration of gravity converting pounds into slugs then the kinetic energy of recoil is determined.

Of all the recoil info stuff I looked at I liked the Robinette info best. In his presentation a photo was shown as powder gas out-accelerated the bullet. Robinette provided 1.7 times bullet velocity to get powder gas velocity. I used the 1.7 in my calcuations.

The momentum would be less as powder weight decreases. The powder gas velocity increase over bullet velocity provides an appreciation of various muzzle brakes.

I had a Vais brake on my .375 H&H and at one time when I fired it other nearby shooters thought I had a KABOOM! Muzzle brakes are noisy but work as they reduce the jet effect of raging powder gas acceleration.

It's as if you put some thought into this…