recoil, real or inferred!!!

[Radny97]

I know this is very nonscientific and subjective but in my personal experience felt recoil has been affected by the following factors in descending order of importance:
1. Weight of the gun. A sub-factor of this is length of the barrel. The heavier the gun and the longer the barrel the less felt recoil for me. Of all the factors this has been the most noticeable factor. (And to the OP's question this seems to me to be the biggest reason why light weight snub nose revolvers like the LCR kick so hard; but I love them anyway ).
2. My grip of the gun. This includes both the way I hold the gun (i.e. The placement of my hands and fingers) the tightness with which I grip the gun, and the actual grips installed on the gun and the ergonomics of the gun. The higher to the bore axis I hold the gun, the harder I grip the gun, and the better the fit of the grips and ergonomics of the gun to my hand, the less felt recoil for me.
3. The pressure of the round. A sub-factor of this is muzzle velocity but as noted in the other posts above, a more slowly burning powder can achieve great velocity without a huge spike in pressure and the resulting snappiness. For example, a 38 special +p with a slow burning powder has less felt recoil for me than a 9mm at the same velocity (all other things being equal). I have noticed this pattern across several calibers and loadings.
4. The weight of the bullet. Compared to the other three above I have found this to be the least influential in felt recoil. However, that is not to say it is not a factor. I can definitely feel the difference between a 230 grain 45 acp bullet and a 125 grain 38 special out of a similarly weighted gun with similar pressure, etc.

I know there will be those who disagree with how I have grouped these factors and the order I have placed them in, but this is my subjective perception of how felt recoil works for me.

 

[highrolls]

tedbeau, your last question is the best thing in this thread. No the recoil would most likely not be the same but you could get them close. Here is the problem with that approach. Not only do different powders have different burn rates, thus different pressure-time curves, they also have different energy losses. For example, the heat energy transfer to the gun metal is just that, a "transfer" and does not contribute to the bullet/charge momentum, and thus, does not contribute to the recoil.

The other problem is "felt recoil" is quite subjective. Lets say you and I agree on a thermometer to use to measure the outside temperture and it is 68 deg f. You say it feels just right, and I say it feels cold and I need a jacket. In spite of that, we can sorta calibrate "felt temperature" and come to an agreement. We will start by jumping in some 33 deg f. water and we will both agree its cold but probably using colorfully different adjectives. We thus ballpark our way to agreement. That is what we have to do to get an idea of a common "felt recoil" measurement.

But where do we start? We cheat and simplify the problem. We really do not need to worry about pressure-time curves of different powders necessarily. When the charge in a cartridge goes off, any energy not used to generate a discharge from the barrel we ignore, well sorta. If we shoot cartridges fast enough, the heat of the gun may become hard to ignore but heat aint recoil. We focus on what we think can become a recoil measurement.

Newton's Third Law of motion. Everything that goes out the barrel has a momentum property that, when totaled, must equal the momentum imparted to the gun. If we keep it simple, no shotgun wads or wadding or cream of wheat in the cartridge, just charge and bullet, we can ballpark it probably as good as our chronometer can ballpark the bullet velocity.

The charge gas drives the bullet out the barrel, and also exits. We can assume all of it exits for calculation purposes even though a small amount of residue remains. The charge momentum is thus the charge weight (even though it becomes a gas) times the charge velocity. For the purpose of these calculations we shall use single base nitrocellulose at a powder charge velocity of 1585 meters per second (5200 feet per second). With the total momentum of all forward moving items calculated, we have the reward; momentum of the gun. If we know the mass of the gun, we can use the classical relationship between momentum and kinetic energy to compute the kinetic energy imparted to the gun.

And this Translational Kinetic Energy we compute is essentially the Free Recoil of the gun. Now the only problem is to determine how to relate this free recoil (remember the temperature measurement above) to "felt recoil". I actually posted some 3-D charts a couple years back somewhere on this forum for typical pistol calibers and pistol weights, but have not done that for rifles yet. I used metrics so the free recoil comes out in Joules.

All that aside, for Doc Holliday, My wife has the same problem. I solved it with 125 grain Penn LSWC bullets over 5.0 grains of Trail Boss in 357 Mag cases and the 357 LCR. I have taken this up safely to 5.3 grains and these approach 38 special + p velocities however the case starts getting filled to the base of the Penn's past that charge weight and do NOT compress this powder. Even when the powder just begins to touch the base of the bullets, very slight compression, I see case splits from the base of the bullet area going up to the top. She loves them and will shoot all I bring, which is a problem cause I like them too.

 

[Frankly]

We tend to want everything to be cut and dry, but felt recoil is not that simple. In addition to factors most have readily acknowledged, the design of the gun can make a huge difference. Likewise with the body mass of the shooter, which is rarely taken into account at all.

 

[wogpotter]

Likewise with the body mass of the shooter, which is rarely taken into account at all.

Very, very true. I was a slim 128~135 Lbs for most of my life, I could fire big boomers all day because they just "pushed me out of the way". My 240Lb friends got way more punishment than that because inertia kept them in one spot.

 

[James K]

When S&W came out with their Scandium .357, an FFL friend told me that the gun shops in his area were full of those guns, like new, each with a box of 47 rounds. The customer fired one shot, fired another to see if it was really that bad, fired a third to prove it, and traded the gun for something else.

Jim

 

[Mike_Fontenot]

The scandium/titanium ultralight S&W snubbies ARE very punishing when shooting even mid-level .357's (mid-500's of ft-lbs or so), but they are a DREAM to carry in a front pocket. And after shooting a couple of .357's in them, .38 non-plus-P's feel like .22's. How many bad guys are you going to need to shoot?

 

[Doc Holliday 1950]

I've read everyone's posts to my question about recoil. The smaller the weapon the more difficult it is to shoot a full P+ or 357 mag load. This all is math and more math plus the type of grip's used. So, the problem as I understand it is to
be advised that if you use a full 38 or 357 load, you will have one or two shots
in a stress moment, you'd probably not feel it or whatever. I can live with this hopefully.
Doc

 

[KyJim]

be advised that if you use a full 38 or 357 load, you will have one or two shots in a stress moment, you'd probably not feel it or whatever. I can live with this hopefully.
Doc

To further complicate things, though, is muzzle flip. The muzzle of a gun may rise or "flip" more in one type of gun than another even if the bullets are of the same weight, same muzzle velocity, etc. This can affect how fast you can get the barrel back on target.

A particular type of gun may have more muzzle flip than another because one barrel has a higher bore-axis than another and cause the barrel to torque upward in the hand more than in a gun with a lower bore-axis where the "recoil" is directed more in a straight line backward. A ported barrel (essentially holes at the top of the end of the barrel) forces some of the exiting gas upward which helps control muzzle flip. Obviously, a lighter barrel will increase muzzle flip even if the overall weight of two different guns is the same.

A .357 will definitely cause more muzzle flip than a normal .38 spl load from the same gun. Best advice is to start with mild or medium .38 loads and work up to .357 magnum. You may find the extra controlability in lighter loads to be more beneficial than the extra energy from a .357 load. Just something to think about.