10mm vs 45acp recoil

[Kronk]

Looking at both cartridges - they are both about the same length, but the 45 has the bigger case and usually a heavier bullet - you would think that it would kick significantly more, but everything I read seems to disprove that.

I realize that in most of the comparisons that I've read there is a big difference in the guns and the loadings, but I'm wondering if there might be some other element that I'm missing, like the effect of bore size on recoil for example. That (all other things being the same) the bigger bore helps the bullet 'squeeze' out easier and therefore kicks less? Am I totally off on this?

[Vitamin G]

Mass...

My .45 1911 will usually shoot a 185grswc at about 950-1000fps (best guess) with a load of bullseye.

My 10mm 1911 will shoot a 180gr jhp at about 1200-1250fps.

(Someone, please, explain it better than me. I took psychology in high school so i could get OUT of physics, and i ended up a therapist)

[Majic]

like the effect of bore size on recoil for example. That (all other things being the same) the bigger bore helps the bullet 'squeeze' out easier and therefore kicks less? Am I totally off on this?

Way off as no matter the size of the bullet the bore will provide the same amount of restriction or a bigger bullet will need a bigger bore, but that bore is just as tight as one for a smaller bullet.
The velocity of the .45 acp is slower than the 10mm. Velocity also plays a big role in recoil. So even though the 2 bullets are about the same size the faster one will have more recoil.

[Ben Shepherd]

Here goes:

I have to use 38 vs 357, as I'm not familiar enough to quote working pressures accurately with 45 or 10mm.

38 with a 158 grain slug: 20,000 psi peak pressure, 850ish velocity.
357 with the same slug: 35-36,000 psi peak pressure, 1300ish velocity.

The only difference is pressure. Higher pressure=harder push. Equal but oppisite reaction. The faster the same bullet gets moved, the more pressure it took to do so. This means basically the faster the bullet goes out the barrel, the harder the gun is going to try and go the oppisite direction, giving you heavier recoil.

Make sense?

[Kronk]

Thanks so much for the replys..

In your examples are both cartidges loaded exactly the same? Obviously, if one has a more powerful load it will kick harder but I was asking what would happen if (in theory) the loadings were also identical. Which means both cartidges are loaded with the same kind of powder, the same amount of powder (you found a middle ground that works in both), behind a bullet of the same weight.

Which would kick more then and why?

[jailbait's_revenge]

if your looking to buy one or the other, from an availablity stand point, i'd choose the 45. 10mm never really took off. and thanks the .40 it probably never will. at the shop i work for we don't stock 10mm, and we're really the only shop within a 3 county radius, other than wally world. in the six months i've worked there, we've been asked about 10mm once, and we had to special order it.

[Peter M. Eick]

If you are a reloader like me, then go for the 10mm. Bullets are cheaper, and you can load the 10mm up to nuclear power levels or down to the 40 short and weak level. I say go for the 10mm.

But then again, I always say go for the 10mm.....

[JIH]

what would happen if (in theory) the loadings were also identical
It more or less goes to the gun then, with one caveat.

Pressures may still be higher depending on cartridge case volume in any given round. Less volume should create more pressure. That's why there's no practical way to load .45 GAP to the level of .45 ACP +p. You can "fit" enough powder to do it, but you'll bulge/burst the case (it's also why GAP cases are thicker).

[Para Bellum]

I'd pick the 10mm over the .45 anytime. It is a much more versatile gun and holds more bullets due to smaller diameter in the same size gun (Glocks eg).

[Bud Helms]

Mass x velocity

[Hard Ball]

The 10mm's recoil sees sharper.

[M1911]

My stainless Kimber full-size is very, very similar to my stainless Delta Elite, except for caliber. The Kimber is .45 ACP and the Delta Elite is 10mm. Shooting full-power ammo in each, the Delta Elite has more felt recoil to me.

[joshua]

The 10mm has a sharper recoil due to higher pressures as mentioned. I've loaded full power 10mm and 45 rounds. When I reference full power I'm talking about 180 grain bullets @ 1200+ fps from a 5" barrel. The 10mm 1911s I have calls for 24 lb recoil spring to tame it. You'll need at least a 22lb recoil spring just to slow down the slide some preventing harsh pounding the frame. I also added shok bufs. The 45 can be the same way if built to 45Super specs. josh

[Axion]

The only difference is pressure. Higher pressure=harder push. Equal but oppisite reaction. The faster the same bullet gets moved, the more pressure it took to do so. This means basically the faster the bullet goes out the barrel, the harder the gun is going to try and go the oppisite direction, giving you heavier recoil.

This is almost right but I just want to clear things up a bit.

If you assume that the force acting on the bullet is constant from the moment the stricker is hit till the moment the bullet leaves the barrel the work done on it by the expanding gasses is; W = F x D or work equals force times distance. (note: F is not actually constant, but for this situation aproximating it as such will not cause signifigant error). Since D is equal to the length of the barel and many bullet makers publish muzzle energy data one an easily solve for the average force exerted on both the bullet, and the gun by the expanding gasses.

Here's some examples:
All based on 5" test barrel
Hornady XTP 185g .45--- (371 ft-lbs)/(5/12 ft) = 890lbs

Hornady XTP 180g 10mm--- (556 ft-lbs)/(5/12 ft) = 1334.4lbs

Hornady XTP 230g .45 +P---(461 ft-lbs)/(5/12 ft) = 1106.4lbs

As you can see, in these loadings the 10mm is going to kick quite a bit harder then a .45.

The take home message is that for similar guns (eq: equal weight and equal barrel lengths) felt recoil is going to be drectly proportional to the muzzle energy of the bullet.


One last thing, the Force calculated here is the average force exerted on the gun and is NOT the force exerted on your hands (obviously). To understand that consider that the time over which that force acts on the gun is VERY short. And since the change in momentum of the gun is equal to the force aced on it times the amount of time the force acts the momentum of the gun won't be that large. Furthermore since the momentum of the gun is what are hands must absorb the force on the shooters hands is more reasonable.

[Kronk]

Thanks Axion, that paints a very clear picture

[Maser]

You can't really rely too much on the whole pressure thing because take a .22LR and a 12 gauge for example. The .22LR actually generates more chamber pressure than a 12 gauge does. The simplest answer is the whole "every action there's an equal and opposite reaction". The bullet tiny bullet moving forward is the action and the heavy gun moving backwards is the reaction. So basicly what that's saying is that the ammount of energy that's moving the tiny bullet at whatever speed it's going is the same energy that's going to be moving the heavy gun backwards on recoil.

[Ben Shepherd]

In my 38 Vs. 357 example the only variable is case capacity. Given the same powder charge the load in the 38 case will kick harder than the load in the 357 case. Why?

Because the 357 has more case volume which would translate into lower working pressure than in the smaller 38 case.

Make sense?

[Kronk]

Thanks Ben.

Sorry to keep picking this but what if - in theory, you had a 45 and a 10mm bore size, but now with the same case capacity?

So the difference in this example, now we shorten the 45 case so that its volume is equal to the 10..

And the powder, bullet weight, AND case capacity are all the same.

Will the bore size difference alone effect pressure/velocity/recoil?

[Maser]

Will the bore size difference alone effect pressure/velocity/recoil?


No. Take a 12 gauge and a .338 ultramag. The 12 gauge has a much bigger bore, but the .338 will have much more "felt" recoil. The bigger the bore, the less pressure there is. It's not different than bike tires. Just look at them skinny tires used on racing bikes. They are about 100 PSI, but yet look at big truck tires. They are only about 25-30 PSI. The more you increase the volume, the less pressure that is needed.