Theoretical recoil is dependent on more than muzzle energy. Recoil in ft-lbs is basically the muzzle energy times the bullet weight (in lbs) divided by the weight of the gun.
I, as an engineer, and a friend that enjoys shooting and is a physics professor, independently developed an expression for the recoil of a gun. He use a totally different approach than I did and we got exactly the same results.
Er = Muzzle Energy X bullet wt (ozs or lbs) / gun weight (ozs or lbs)
Then a member that has a recoil calculator compared my numbers to his calculator values and we were within 10%.
Things that were not accounted for is slide mass etc, and no attempt was made to isolate muzzle flip.
I had been shooting 9mms for years, and finally bought a G22 (.40 cal). It was incredibly different than a G17. It was lifting, torquing, and recoiling significantly more than the G17. I was shooting range ammo in both.
Recently, I spoke with a guy that also shoots a lot, trains SWAT members etc. and he agreed 100% that the .40, in a given gun, has far more recoil and he mentioned torque, than a 9mm.
IIRC, using my formula, based on range ammo, the Glock 22 has about 50% more recoil than the Glock 17.
There is some confusion about this because different people perceive recoil differently. It doesn't mean the recoil isn't there or somehow got magically reduced of multiplied, it just means that two people 'feel' it differently. It also does not mean that the effect of the recoil was not present, it just means we don't realize it is.
Recoil is not something that changes just because one person feels it more or less than another. The recoil is constant, based on the muzzle energy, bullet mass, gun mass, and a few other characteristics of the gun. All that is transferred to the shooter. How much it affects the shooter is the variable.
So according to this you can't reduce recoil with a tungsten guide rod (recoil spring) because it would have no effect on your three variables (except to slightly increase the overall weight of the gun), but the claims are that they "greatly reduce the recoil you feel" according to one website. So you're saying the tungsten rod only alters the perceived recoil?
Originally Posted by Tangle
Additional variables with autoloaders that affect perceived recoil include the weight of the parts that are reciprocating (slide, bolt, gas pistons) and recoil springs which are compressed during the recoil cycle. The springs in particular affect the rate at which the slide (bolt, etc) moves, which can alter the duration of the recoil pulse felt by the shooter.
Originally Posted by Tangle
Now an interesting thing to note - The new M&P Shield is one where I have shot the .40 and 9mm side by side and for that model I found no discernable difference in recoil between the two. So I think that Smith and Wesson did something amazing. And I want a Shield too and I think I'd do the .40.
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A couple of things here. My calculations and the recoil calculator that gave results within 10% of mine do not take into account muzzle rise, weight distribution, or the center bore line distance to the pivot point of the wrist.
Originally Posted by oldrwizr
In order to take all that into account, one would have to know measurements, weight distributions, and a number of other parameters and it would get quite complicated, too much so, for most of us.
But, when a bullet is accelerated down a barrel, the total recoil energy can be estimated by my formula. The formula is especially useful for comparing two similar guns, e.g. a G17 to a G22, or different loads in the same gun, i.e. 115 gn, 124 gn, 147 gn etc.
The tungsten rod adds weight at the best possible place - near the muzzle of the gun. That should reduce muzzle lift. But if you put one in a G17 and another in a G22, then the effect is a wash and the .40 will still have a lot more recoil than the 9mm.
One thing to notice in these not shock absorber type recoil reducers is that you never see numbers with them. There used to be a company that made guide rods filled with mercury and they put some numbers, 25% IIRC reduction. Well, that got my attention so I called and asked how they measured the recoil. They said, "We haven't measured the recoil." How about that! So my next question was how did you arrive at the 25% reduction value? They said they were just going by feel, no measurements, just feel. I bet there was no bias in their 'feel' analysis either :rolleyes:.
So with the tungsten guide rod, the recoil would be reduced by the additional weight of the guide rod, but now we have a heavier gun to carry around. Why not just buy a Sig instead of a Glock and have a much heavier gun with proportionally less recoil? Well, that's an over simplification, price, characteristics, and preferences all play a part, but the point remains that a heavier gun has less recoil. The tungsten rod makes the gun heavier and hence has slightly less recoil.
But it likely would more than proportionally help with muzzle lift because of where the added weight is located. It may be that's what people are noticing. And, that is and important attribute of recoil. Since the weight is near the muzzle, energy would be dissipated by having to lift the weight against the mechanical leverage of the gun.
But, as I understand it, that isn't what this thread is about. It is about choosing between a .40 or a 9mm and how much difference there would be in recoil. So we would be comparing, I assume, similar guns, e.g. G17 & G22. For that case, all the gun parameters are the same so the formula should be pretty indicative of the difference in recoil.
Very true, but what we 'feel' is not a measure of actual recoil that affects the motion of the gun in recoil.
Originally Posted by gasmitty
What are the gun weights, bullet weights you were shooting, and the energy of the bullets?
Originally Posted by accessbob
Msc8127....timely comments on the 300's. I don't want to steal the thread but I just found a steal on a Weatherby 300. I've got the same gun but in win mag. I was going to put a friend of mine on to the Weatherby but he's fairly green. Wouldn't do. Maybe I'll sell him mine and I'll get the other.
Sorry for the digression.
It isn't just the weight and velocity of the bullet, but the weight and pressure of the propellant coming out of the barrel as well.
* Type of bullet .... the harder the bullet, the more recoil
* Heavier bullets .... a 147 gr kicks more than a 115
* Barrels ............... Rohrbaugh freebores their 9mm. Others use enlarged lands
* Powder charge .... a +P round kicks more
* Blowback ........... A blowback has more felt recoil than a lock breech
* Bullet diameter .... a 32 can range from .309 to .312 .. tighter bullet means more kick
* Heavier gun ....... That equals less felt recoil
Most recoil arguements come from the new pocket pistols. Shoot a micro 9mm and your big guns recoil will disappear
I've fired the 9mm 127 grain +p+ Winchester Rangers and I think they are still less "snappy" than the 180 grain .40 loads. Guns were a Glock 19, Glock 23, and a SIG SP2022 in 9mm. I have no experience with micro pocket guns.
I've noticed with 9mm rounds, the 115 and 124 grain stuff seems to have more snap or muzzle rise than recoil, while the opposite seems to be true for the heavier, slower 147 grain bullets. Very little muzzle rise with a smooth, hard push from the 147 grain stuff. YMMV...
The tone of this post is the way I think of recoil.
Originally Posted by accessbob
I pick a gun, ammo, go to the range (woods) and shoot. After I see the way that any particular gun/ammo feels, then I draw my own conclusions based on that. The numbers mean nothing to me.
Besides, its more fun for me to shoot than it is to do math..... 125gr of .357sig at 1450fps is impressive though!
I did that little 6'' circle at 6-7 yards "test" again yesterday and included a .357 Sig, so it's a 26, 27, and 33
Originally Posted by CDW4ME
All have a 8# NY trigger and Pearce magazine baseplates.
I used factory 180 gr. S&B FMJ (no chrono data) and Remington 165 GS (1,018 fps) in the 40
The .357 Sig was loaded with my handloaded Gold Dot 125 (which chronographed @ 1,230 fps about 85 fps less than factory ammo).
In the 9mm I used my handload which is a 115 gr. Hornady XTP @ 1,157 fps average out of the 26.
I put XS Big Dot sights on the 27 & 33. I had them on a previously owned Colt 1911 and thought they were an asset at my typical 6-7 yard shooting. The 26 has Meprolights.
Subjectively, the 26 kicks a lot less than the other two. Subjectively, I thought the 33 was kicking slightly more than the 27.
Again, the timer session involved a 6'' circle stuck on a larger B-21 target at 6-7 yards away. (My standard)
I had a lot less difficulty keeping the 9mm hits on that 6'' circle at the limits of my ability to control recoil.
With the .357 and 40 I had to "disqualify" some pairs and repeat because a subsequent shot failed to hit the circle; with the 9mm all shots hit.
I was a little slower overall yesterday than last time, but the end results were the same.
The "qualifying" average 1st - 2nd shot times for at least 9 pairs (18 rounds) were:
Glock 26: .28 sec.
Glock 33: .36 sec.
Glock 27: .40 sec. :turtle: :icon_cry:
1. Yes, I'm slow :turtle: ; I can pull the trigger faster, but the result is more hits failing to land on the 6'' circle; if I was satisfied to just make hits anywhere in the "coke-bottle" of a B-21 target then this comparison wouldn't matter.
2. My impresion that the .357 Sig had a little more recoil than the 40 was inaccurate (PF calculation holds true); the difference may be small, but it is there.
3. I did this a few weeks ago with the same result, only I averaged .25 with the 9mm that time. The .357 and 40 times were closer to the 9mm last session, so the XS Big Dots did not (unfortunately) decrease my shot to shot time.
4. I was packing the 40 prior to the last session; I prefer the larger bullet. However, if I wanted to be objective, the 9mm was the quickest and most accurate of the three in my hands. As much as I hated to do it, I started carrying the 9mm; yesterday reinforced the choice again.
If I slowed down to .5 - .6 between shots then I would likely keep all pairs on target with any of the three; it may sound impossible, but I can tell the difference if I take an extra 1/4 sec.
Whether fractions of a second in follow up shot time are important is something that depends...
Crap, now I'm starting to 2nd guess myself :ponder:
With these two cartridges? What recoil?
May I offer an old-school suggestion? Beg or borrow a .44 mag revolver and get 4 50 round boxes of the hottest loads you can find. Go shoot them all in less than one hour. I guarantee recoil will never bother you again.
Maybe some of the more modern types could borrow a .500 S&W mag and do the same thing. I won't guarantee the outcome though. :image035: