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I have been loading 9mm (124 grain west coast) and 45 acp (200 grain west coast) bullets for use in IDPA. I am currently using Winchester 231 powder, primers and mixed range brass. Power factor is around 135 for the 9mm (ESP and SSP) and 175 for the 45 acp (CDP). I was recently told that if I use a heavier bullet, ie. 147 grain 9mm and 230 grain 45 acp, that I would experience less felt recoil. I could not find any info regarding this statement and was wondering if anyone has any info to confirm or deny this.

Andy J
 

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The heavier bullets will shoot softer. There is a noticeable difference with the 147 gr 9mm vs the 115-124 gr bullets loaded to the same PF. Same for the 230 vs 200. Someone posted a formula on either this forum or Glocktalk.
 

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I dunno, I don't really notice a whole lot of difference in my 45, but w/ most rifles and shotguns, the heavier bullets/projectiles kick MORE. Seems sort of odd that that would be different in a handgun...
 

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Using the posted formula above, I used a Speer manual and calculated recoil from the 185 gr jacketed, 200 gr hp, and 260 gr hp, and got highest recoil with the heaviest bullet. The manual is Speer # 11.

I have found that the heaviest bullets recoil the most. Not scientific but just what I have shot or calculated.
 

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Heavier bullets will recoil less when loaded to the same PF as a light weight bullet. Same velocities for the given bullets will yield different results! Just load up a few and try it.

Paul
 

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Although I've not done any testing on this, my subjective experience has been that heavier bullets produce greater recoil than lighter bullets. I guess it's possible that loaded to the same PF (i.e. less velocity for the heavier bullet) the recoil perception could be different.

Certainly is an interesting area for some "objective" testing. :)

Good shooting.

Rod.
 

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Bottom line is with relatively short barrels (<5") on a 1911 you just have to try them for yourself. I've read about the scientific formulas and all the mumbo jumbo and figured just load up a few hundred of each then go to the range.

I too am using Western bullets and have started playing around with 200gr vs 230gr using WST and W231. IMO the 200 grain has less felt recoil but the operative word here is felt.
 

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I am not a competive shooter so I never thought to fix the power factor. When you do this, and you increase the bullet weight you will cut the recoil somewhat.

I just compared starting and max loads for differing bullet weights and found that recoil goes up with bullet weight and so does power factor.
 

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Constant power factor

The key in this equation is a constant power factor. The recoil will be more for a heavier bullet at the same velocity. However, given 230 vs 200 and the decrease in velocity required of rthe 230 it is possible to have less recoil. Physics, for every action there is an equal and opposite reaction.....
 

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The physics governing recoil and relative motion of the gun and bullet after firing are called "impulse-momentum" equations.

They are based on calculations of momentum, which is mass times velocity. Not that M*V is the basis for power factor calcs.

Energy is related, but does not govern the equations of motion of two objects in collision or separation.

So bottom line - for a given velocity, recoil will be greater for a heavier bullet.

Experience bears this out also. Just try it.
 

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True for a given velocity the impulse momentum equations dictate a heavier bullet will have a greater recoil. However, the velocity isn’t constant. Nothing like good old physics or Dynamics. I assume power factor is just a straight multiple of bullet weight in grains times velocity in feet per second divided by a constant. This would really be interesting if instead of Power Factor they used kinetic energy, which is a truer comparison.
 

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BTW, the reason for not using kinetic energy is that it's so dramatically velocity-biased. Literally everyone would shoot the lightest bullet weight allowed if an energy-like metric were used instead of the momentum-like "power factor".
 

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Guys, a heavier bullet loaded to the same PF as a lighter one will have a softer recoil. If this were not true then every Grandmaster/Master level shooter in IPSC Limited would be shooting a 135 gr. bullet in their .40 rather than a 180 gr. bullet.
Good example is the Winchester 115 gr 9mm white box ammo. This ammo has about a 130 pf. A 147 gr bullet loaded to the same pf has a significantly softer recoil.
Of course the recoil will be more with the heavier bullet if you load say a 230 gr. bullet to the same fps as you do a 185 gr. one.
 

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Joe D
You hit the nail on the head. Thanks.

Others,
With the moderate recoil from a 45ACP you just have to load up some different bullet weights to see what FEELS good you. The opperative word is FEELS cause it's all about preception.

The impulse is different so go with what works for your type of shooting.
 

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In theory lighter faster bullets have more felt (sharper) recoil but less muzzle rise. Conversely, heavier bullets supposedly have softer felt recoil but more muzzle rise. Most of the top IPSC shooters use 180 gr. bullets but a few shoot 200 gr. In the .45 I've tried 200 gr. and 230 gr. bullets but never saw that much difference when they were loaded to the same power factor. After a mag or two they feel the same. The question in this ongoing debate it probably which bullet is better for sight tracking, especially in fast competitive shooting. The one big difference I have seen is that lead bullets seem to have less felt recoil than fmj.
 

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This makes me wonder what exactly felt recoil consists of? How much of the perception of recoil is simply due to the hand being pushed back by the pressure of the burning powder in the chamber and barrel (the explosion, in effect), how much is due to the slide being cycled back against the recoil spring, how much is due to muzzle blast as the bullet exits the barrel (actually a huge drop in gas pressure, but with resultant forces applied I presume) and how much is due to the slide being snapped forward again by the recoil spring after the shot (quickly enough for the average shooter trying to regain the sights to interpret as part of the recoil)? It seems to me that there are a number of such factors that combine to make up felt recoil, and that it is balancing these factors that determines what you feel and perceive. Although keeping power factor constant and varying powder charge to bullet weight makes sense, I would expect that the burn rate of the powder used, the recoil spring weight, and whether or not there is a compensator are also going to play a role in the amount of recoil perceived for the individual within those parameters.
 

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I think in typical autoloading calibers, what really matters isn't recoil per se but a lot of the things that accompany it.

The most obvious of course is muzzle flip, which we would like to minimize or at least control to improve sight recovery. There's also muzzle blast, which is a much greater contributor to flinching and blinking than the actual movement of the gun. Not coincidentally, the heavy bullet/fast powder loads favored in practical shooting minimize muzzle blast for a given PF, though the characteristics of individual powders vary as well (eg: Titegroup is more "blasty" than N320). Also something I've noticed is in certain guns, particularly snappy recoil patterns can lead indirectly to various painful events. Having your trigger finger dragged across a serrated trigger, having your thumb bumped by a sharp slide stop, having your hand be abraded by aggressive grip checkering, etc.

So to me, anyway, "felt recoil" consists of all those things: muzzle flip, muzzle blast, and various pinches, pokes, bumps and scrapes. And again not coincidentally, I've found heavy bullet/fast powder loads to do a good job of minimizing those factors.
 

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Let this be a lesson to you all. Never talk to a mathematician about anything with formulas. If you have courage to continue here goes.


* = times

1) Recoil impulse = ( Bullet wgt * Bullet velocity + 4000 * Charge wgt) / 22540

2) Gun velocity = 32.2 * recoil impulse / Gun Wgt

3) Recoil energy = Gun weight * ( Gun velocity squared) / 64.4

Notice that in formula 1), Bullet wgt * Bullet velocity is the power factor undivided by 1000.

When you fix the powder factor in 1) and increase the Bullet wgt to keep the powder factor constant you have to drop the bullet velocity the same percentage. When you go to a heavier bullet and drop the velocity you have to cut the weight of the powder charge. This will drop the recoil impulse. This causes gun velocity to go down, along with recoil energy.
 
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