Recoil comparison question

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rmcda

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Hi -

Anyone out there know which would have more felt recoil?
Both are factory loads.

a 232 gr bullet, muzzle velocity 2625 / energy 2551

a 286 gr bullet, muzzle velocity 2362 / energy 3544

Both have similar trajectory out to 300 yards.
 
rmcda said:
Hi -

Anyone out there know which would have more felt recoil?
Both are factory loads.

a 232 gr bullet, muzzle velocity 2625 / energy 2551

a 286 gr bullet, muzzle velocity 2362 / energy 3544

Both have similar trajectory out to 300 yards.
Click to expand...

With the same mass rifle and no muzzle brake the 2nd heavier bullet will have about 39% more recoil.
 
286 generally, but you said "felt recoil" which also involves stock design. Respectfully Jim. But I assume you are using the same rifle.
 
Thanks .. yes same rifle, but I should have just said recoil as I understand other factors, i.e. overall rifle weight, buttpad, stock design makes a difference.
 
Gmwebs said:
Barrel length would be irrelevant as we already have the muzzle velocity. The only thing can change felt recoil at this point would be mass and/or brake (or I guess a buttpad)
Click to expand...

I believe more umph is required to get a projectile up to a given speed given less barrel in which to accelerate, as it would require a greater rate of acceleration.
 
The heavier bullet has the greater recoil, but the difference is minimal, something on the order of 4 ft-lbs recoil energy, and 1 fps recoil velocity in an 8 lb. rifle. Weight of the powder charge factors in to recoil calculations as well.
 
Please help me identify the flaw in my logic.

A given gun with a given cartridge will fire a given projectile at a given muzzle velocity. If you cut the barrel down, you will see a reduced muzzle velocity. To maintain the same muzzle velocity with the reduced barrel we would need an increased amount of gunpowder, thus more umph.

Please help me understand why this theory is wrong
 
popcanhunter said:
Please help me identify the flaw in my logic.

A given gun with a given cartridge will fire a given projectile at a given muzzle velocity. If you cut the barrel down, you will see a reduced muzzle velocity. To maintain the same muzzle velocity with the reduced barrel we would need an increased amount of gunpowder, thus more umph.

Please help me understand why this theory is wrong
Click to expand...

It is far simpler, and far more complicated. All that matters to calculated recoil in the end is the amount of kinetic energy the bullet and powder expelled from the barrel contain. More energy expelled in one direction, means more energy driven in the other.

Because powder charges vary, that contribution to the equation is difficult to assume. More powder of any given type will mean more kinetic energy represented by the powder, but different powders mean different volumes. There is a maximum level of any given powder that can be safely shot in any given case/chamber/caliber. If you are at that maximum, there is no way to increase the powder level to "get back" the velocity lost in a shorter barrel. Usually, however, the powder that produces the highest velocity in a long barrel will also produce the highest velocity in a shorter barrel (within reasonable limits, of course) so you can't necessarily just "increase the amount of gunpowder" with any given load, and it may not be possible to gain any velocity by changing powders if pressures are already at maximum.

The speed and mass of any given bullet will allow an accurate calculation of its kinetic energy to add to the total.

It should also be remembered that "felt recoil" is something impossible to calculate.
 
Sorry - have to ask same question again - reason is I found out that the Norma website has incorrectly posted muzzle energy for the 232 oryx at 2551, when it should be 3551,
so if you would be so kiund to take another look at my question with the revised energy number.

Thanks

rmcda said:
Hi -

Anyone out there know which would have more felt recoil?
Both are factory loads.

a 232 gr bullet, muzzle velocity 2625 / energy 2551

a 286 gr bullet, muzzle velocity 2362 / energy 3544

Both have similar trajectory out to 300 yards.
Click to expand...
 
Ok, so if 2 guns shoot the exact same projectile with the exact same muzzle velocity, but one has a 28" barrel and the other a 4" barrel, would the 4" gun not require more powder than the 28" gun? I'm sure it would. And would this increase of power not result in increased recoil?

If so, recoil cannot be quantitatively compared using gun mass and muzzle velocity alone, bit would also require barrel length.
 
Barrel length is irrelevant, except as it adds to gun mass and affects "felt recoil". The calculations of actual recoil force and velocity do not need to include it.
 
rmcda said:
Sorry - have to ask same question again - reason is I found out that the Norma website has incorrectly posted muzzle energy for the 232 oryx at 2551, when it should be 3551,
so if you would be so kiund to take another look at my question with the revised energy number.

Thanks
Click to expand...

OP, you can tinker to your heart's content on this site: http://www.handloads.com/calc/recoil.asp

Using a 9lb rifle and identical charge weights of 75gr (which won't be correct, the 286gr load will have less powder), the 232gr load will have 29ft-lb of recoil energy and the 286gr load will have 33.5ft-lb for an increase of 16%.


popcanhunter said:
Ok, so if 2 guns shoot the exact same projectile with the exact same muzzle velocity, but one has a 28" barrel and the other a 4" barrel, would the 4" gun not require more powder than the 28" gun? I'm sure it would. And would this increase of power not result in increased recoil?

If so, recoil cannot be quantitatively compared using gun mass and muzzle velocity alone, bit would also require barrel length.
Click to expand...

Barrel length has nothing to do with it, the muzzle energy and weight of the bullet and powder charge are what matter. Your extreme example would need a much greater powder charge for the 4" barrel, which would result in more recoil energy, as you are thinking. But it doesn't have anything to do with the acceleration needed to get the same muzzle velocity, it is because of the extra powder weight. Play with the calculator I linked to above, it will show you that the results are quite sensitive to the powder charge.

The amount of recoil energy is related to the muzzle energy and momentum of the bullet and powder charge. This is why two loads with the identical muzzle energy but different bullet weights will have different amounts of recoil energy.

OP's question is a good example of this. The two muzzle energies are virtually identical, only differing by 0.1%, but the heavy bullet weighs 23% more and produces 16% more felt recoil (assuming the same powder charge, which is conservative). Even reducing the powder charge for the heavy bullet load to 70gr still gives us a free recoil energy of 32.2ft-lb, an 11% increase.



Mark
 
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