Reading over a lot of threads and info on reloading, I've read on more than one occasion where one powder recoils either more or less than another powder.

Assuming someone is talking about the the same bullet moving out at a comparable velocity, with the only difference being the powder used, is that possible?

I would assume simple physics regarding the weight of the projectile, velocity and the weight of the firearm would be the only determining factors.

Can anyone speak on this from experience? Is there more at work here than I'm thinking?

If you look at a typical list of loads for the same bullet listed in order of max muzzle velocity, you will notice that it falls roughly in the same order as burn speed. The slowest powders will have the highest velocity. Keep in mind that the data is predicated on a fairly long pistol barrel in pistol calibers. Hodgdon uses a 7.7 inch barrel in the .38 special I was looking at.

Again, in general, the faster powders are known for lower recoil. Of course, an extremely short barrel can throw a monkey wrench in works.

Don't forget the WEIGHT OF THE POWDER!!

The real physics answer is that the AMOUNT of powder used has a substantial effect on recoil because the powder has MASS and comes out faster than the bullet itself after the bullet departs! (Think rocket motor).

When I use a slower powder, I have to use MORE POWDER, sometimes twice as much mass, to get the bullet up to the same speed. And that added mass of powder goes OUT and pushes BACK (Ref Sir Issac Newton) giving more recoil.
Recoil Calculator

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Science plus Art

If the burn just peaked, and that was it, no difference at all. The shape and time of the pressure curve also makes a difference, as well as the temperature of the burn and the volume of hot gases as well as the mass and velocity of the bullet fired. Of course the gun balance, barrel length, type of action and weight figure in, too. We all have differences in the way we feel recoil. All of this being different can lead to perceived quicker (sharper) or slower (softer) feeling recoil.

I was looking for a soft shooting load for 9mm and was advised to try a 145 grain lead bullet with a light charge of Acc #7. I had tried 'light' combinations before and was unsatisfied but the ease of shooting the #7 with a heavy bullet was VERY noticeable. It immediately because my favorite 9mm soft recoiling load.

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"He was kinda funny lookin'"

I agree with the Physic and equations but in reality how much difference in recoil can there really be if using a bit more powder?.

Say the difference of 16 grains VS 6 grains when dealing with a 158 gr bullet?. (H110 and Titegroup) 357 mag.
Yes, the extra 10 grains works into the equation but to me the extra velocity is what makes the recoil different.

Also the platform, revolver vs locked breech vs blow back changes the felt recoil.

For the OP there was a long thread on this recently.

This article explains what OKF is a referring to.

Power Factor & Recoil: Which Bullet Weight Gives You the Edge? - Shooting Times


The formula for ammo with the least recoil is to use heavy bullets in combination with a gunpowder than produces the least recoil. Which gunpowder does that? Select a gunpowder that requires the smallest charge weight to achieve your desired velocity, because less gunpowder weight for the same velocity means less recoil. Check your reloading manual for that information.

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Still Running Against the Wind

In addition to the above, a lot of people associate muzzle blast and flash with recoil. Even though the bullets velocity may be the same, a powder like 296, that uses a charge weight say twice that of a faster powder, will subjectively recoil more to most people. Partially do to the greater mass of the powder charge, mostly do to the muzzle blast.

Larry

That is easily demonstrated with the referenced recoil calculator.
I put in a 3# gun with a 158gr bullet at 800fps. Load 1 was 4gr powder, load 2 was 8gr of powder. This represents load 1 fast powder and load 2 slow powder, same resultant MV.

Load 1 produced 2.14 ftlb free energy, while load 2 produced 2.65 ftlb free energy, an increase of 23.8% in free energy just from the extra 4gr of powder. Try it yourself and see:
Recoil Calculator

Now what will that feel like to your hand vs my hand? I have no idea. Like rwsmith said, I notice the difference.

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Science plus Art

The "assumption" is that both load produce the same velocity of 800 FPS? for a difference of only .51 ft lbs

I would have to see what powder(s) can be double the amount and produce the same velocity.?

I finally found the thread I was looking for kinda like Deja Vu all over again.

It's all in here somewhere.

Physical differences and Recoil.

Recoil Comparison: Pistol Competition Cartridges - Handguns

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Still Running Against the Wind

That mass of powder has to go somewhere after it is burned. Since all the oxygen is self-contained, there won't be a significant gain or loss of mass in the process. It is also going faster than the bullet once it leaves the muzzle, so there is a force multiplication effect. Most of the recoil comes from accelerating the bullet, but not all, otherwise there would be no point of porting or using a compensator.

The force of recoil (distinguished from recoil energy) is the change in momentum with respect to time. A fast burning power which accelerates the bullet quickly will produce a greater force than one which burns gradually.

That's disguised to a large extent because we tend to use less of a fast burning powder (e.g., Bullseye) than of a slower one (e.g., 2400), producing less velocity, hence less recoil.

It would not be hard to measure recoil as a function of time with a test barrel, but I'm not of any studies to that effect. It might be interesting to ask someone who blew up a pistol or revolver if it felt any different, assuming they're still around to ask. There are plenty of examples of people firing multiple times into a plugged revolver, thinking each time was a squib or misfire.

Very interesting. Thanks for the info and links. I have several different powders that I'm going to try for my 9mm, so I will be curious if they "feel" different to me.

And with a handgun, the forces in line with barrel is multiplied by the distance (lever arm) between center of the barrel and the "center" of your grip
Causing a rotation or muzzle whip

Gripping a hand gun higher....reduces this felt recoil

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I'd like to agree with you BUT

Again, you can not argue with Physics, but?

Using Hornady Data (which we will take as valid)

For a 9mm load and 124 gr Bullet listed FPS of 1050 fps

Unique load is 4.7 grains
AA # 7 load is 7.2 grains

A difference of 2.5 grains

The "recoil" of the AA 7 load will be more or actually "felt" due to the 2.5 gr difference????

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Still Running Against the Wind

I just gotta say..as an example... a 240 gr bullet at say 1000 Ft per second will generate X amount of recoil from the same gun... and the average shooter won't be able to tell the difference if the powder charge is 4 gr or 8. Heck guys there is quite often more difference than 4 gr between bullets in a box. Heck I was weighing some 30 cal 190 match bullets the other day and there was a swing of more than 3 gr in the small amount I weighed. And the length of burn on the powder can't be determined by our hands. The only thing that makes one load different from another... all things being equal.... is that thing between our ears. We think and feel what we want to believe. When I got my first chronograph I checked thousands of rounds of weighed charges of shotshells to find the best loads for my purposes... I was anal about it. I found out that the load I liked the best cause it had the least recoil was averaging 60 Ft per second less than the books said.... yep it did have less recoil... and velocity of course. 1200 FPS with an ounce and an eighth of shot out of the M-12 Trap gun had the same average recoil no matter which powder you used. If we feel less recoil from a certain load with the same velocity as another with the same bullet from the same gun, it is because we believe we do ie we lie to ourselves. Now I do feel in my mind recoil is cumulative. In the course of my job I shot 3-5 thousand shotshells over a weekend... At the end you were TIRED. And I was a teenaged shooter. The ol guys I shot with were whupped. lol

Certainly is possible. I have chrono several diff powders in 9m, 40 & 45, all reaching the same vel. Felt recoil can be quite diff between diff loads. Take WST as an example. I find the recoil impulse quite soft compared to TG or RD, pretty much the same charge wts within 1-2/10. Probably something to do with the pressure peaks, not just charge wt, just guessing.

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NRA Cert. Inst. IDPA CSO

I am thinking pressure curves, peaks whatever has more to do with it. Using the recoil calculator, a few grains of powder differance is insignificant.

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Still Running Against the Wind

The greater the mass of the powder, the greater the recoil.

But real men don't worry about it.

That works for powders at extreme ends of the burn rate chart but doesn't explain powders within 1/2gr charge wts???

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NRA Cert. Inst. IDPA CSO

With all things being equal, outside of the weight of the powder charge, I firmly believe that very few if anyone would be able to tell a real difference in recoil. In other words, I believe it's all psychological, and I'm sure a blind test would validate this. Yes, pressure curves do vary, but we're talking a fraction of time that is so short, the human mind would be incapable of discerning it, at least in the pistol world. Loud reports and excessive muzzle flash can/will fool our brain into believing the recoil must be more severe. The human mind is a funny and unreliable instrument when it comes to things like this, and can be easily fooled by other influences.

Saying all that, perhaps someone who shoots tens of thousands of rounds a year could be in tune to tell the difference, but that would be the only possible exception to my belief. Again, this is with everything being equal, which in itself is rare in the shooting world. There is almost always a difference in velocity between two different powders and this difference will result in different recoil factor to a well tuned shooter.

That's my story and I'm sticking to it.

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So many S&W's, so few funds!!

The numbers are pretty clear.

Look at the numbers for these two loads:

Load 1: 9 gr fast burning powder, 125 gr XTP, 1300 fps

recoil impulse = .88 lbs sec
recoil velocity= 14.18 fps
free recoil energy = 6.24 ft/lbs

And

Load 2: 19 gr slow burning powder, 125 gr XTP, 1300 fps

recoil impulse = 1.06 lbs sec
recoil velocity= 17.04 fps
free recoil energy = 9.01 ft/lbs


Now... let's assume the same velocity and the same 9 grain powder charge but add the extra weight to the projectile and see what happens:

Load 3: 9 grains powder, 135 grain bullet, 1300 fps

recoil impulse = .94 lbs sec
recoil velocity= 15.11 fps
free recoil energy = 7.09 ft/lbs

You'll note that 10 grains of powder (load 2) has a much more profound effect than 10 grains of bullet (load 3) on the recoil numbers.

Why? Because the powder still has the same mass, whether it's still in solid or gaseous form, BUT that mass of powder exits the barrel a lot faster than the bullet - about 3 times the muzzle velocity on average. Consequently, to get the approximately the same recoil as the 125 gr bullet with 19 grains of powder, using just 9 grains of powder you'd need to launch a 155 gr bullet.

Load 4: 9 gr powder, 155 gr bullet, 1300 fps:

recoil impulse = 1.05lbs sec
recoil velocity= 16.96 fps
free recoil energy = 8.94 ft/lbs

(very close to Load 2)


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Now there's a little more to it as well, as there's also the myth that slower powders always produce more velocity and that's not always the case.

For example in a 3" .357 I've found that 9 grains of Unique will give me an average velocity of 1,300 fps with a 125 gr XTP. In contrast a maximum load of 296 will only give me 1140 fps in the same 3" .357 with the same 125 gr. bullet.

And that's interesting as that max load of 296 with a 125 gr bullet at 1140 fps produces more recoil than the 9 gr load at 1300 fps:

Load 5: 20 gr 296, 125 gr bullet, 1140 fps

recoil impulse = .99 lbs sec
recoil velocity= 15.89 fps
free recoil energy = 7.84 ft/lbs

That is very significant as unless you actually have and use a chronograph, you'll swear Load 5 is producing more velocity than Load 1 as you're feeling more recoil, even though Load 1 is 160 fps faster in a short 3" barrel.

That's the basis for the gun rag and internet myths that slower powders always produce more velocity. More recoil yes, more velocity - not always.

Well I have never gotten higher vel with faster powders in any caliber, any bbl length. Pretty close yes, but not faster, even in snub 357mags.
Yes, some one that shoots a lot can tell the small diff in recoil impulse & it doesn't take 10s of 1000s of rds a year. Yes you have to shoot more than 50rds a week to pick up on this but it is noticeable. Why so many shooters in competition are always looking for that perfect load that shoots small groups, meets PF & produces less recoil.

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NRA Cert. Inst. IDPA CSO

All those numbers make my head hurt....

I'm just going to go shooting ....overthinking isn't any fun.

Absolutely.

It's far better to just base what we think we know on rumor and wives tales rather than using actual data to drive our decision making process.

Better to do it easy than do it right.

As the author states in your linked article:

"Also, the ammunition might be loaded with different gunpowders, and that can affect recoil force even if they push the same bullet to the same velocity."

I've certainly noticed this phenomenon. It is not always noticeable, but I've experienced it the most in 9mm with heavy bullets and loaded to minimum velocities. Slower powders had noticeably softer recoil. I just always assumed it was due to "duration". That is, the time period over which the energy is released.

Shooting 147gr cast LRNFP loaded with Universal were noticeably softer shooting than the same bullet loaded with a faster powder like Bullseye. In my Springfield 1911 it was almost like you had to wait for the slide to finish cycling.

I've noticed it at other times too, but only with low velocity loads were it makes sense it would be the most noticeable.