Differences in Recoil but Same Bullet Weight

[WrongHanded]

This does involve my reloads as well as factory ammo, but it's really a question about components and how they can effect recoil.

I decided to shoot some Double Tap .357 Mag 158gr "Bonded Defense" (looks like Gold Dots) at the range recently, along side my reloads. They are an SNS 158gr coated LSWC with 14.5gr of 2400 and a CCI SPP. I can't currently remember what the manual was claiming for velocity on the reloads at that charge, but it is certainly less than the Double Taps claimed 1,400fps from a 4" GP100 (which happened to be what I was using).

Now I didn't chronograph these rounds, but I felt an obvious increase in recoil with my reloads to the DT ammo. And I'm wondering, other than velocity, what could cause that? Different powders, jacketed vs coated lead, or something else?

 

[Bat Rastard]

I would try to get one of them over a chronograph. If they are kicking more than Double Tap they might be pretty hot.

 

[fxvr5]

Powders and recoil: https://www.ssusa.org/articles/2017/6/19/gunpowder-selection-for-controlling-recoil

Bullet type can also affect recoil because they require different amounts to reach the same velocity. In general, jacketed bullets require more powder to reach the same speed as lead bullets, so jacketed bullets produce more recoil than lead for the same velocity.

 

[murf]

nope, just velocity.

murf

 

[fxvr5]

nope, just velocity.

Incorrect. See the link posted in #3 above.

 

[mcb]

First you have to measure velocity. If both bullets are the same weight then the most likely cause of a difference in recoil is velocity.

But as the article the that fxvr5 links to if you have the same velocity but achieve it will less propellant that load will have less recoil and usually that feels better to the shooter. The propellant mass play a part in the recoil as it is mass being ejected out of the muzzle. Propellant play a bigger role than it mass alone would suggest due to the fact that a sizable portion of that mass ends up leaving the barrel faster than the bullet If all else is equal (velocity and bullet mass) then the load with the lighter powder charge will have less recoil. With most pistol loads this is pretty minor but if you are shooting a lot you will probably notice it.

Case in point, that really brought that reality home to me earlier this summer. I was working up a 240gr XTP load for my Model 29 44 Mag revolver. I tried Hodgdon H110, IMR 4227, and for giggles IMR HiSkor 800-X. The results where an eye opener.

The 4227 ended up well below where I wanted to be so I will leave it of this discussion.

Charge Weight: 23.5 gr H110
Average: 1351 fps

Charge Weight of 14.0 gr 800-X
Average: 1372 fps

The thing is the 800-X despite being slightly faster was noticeably more pleasant to shoot. The recoil was lighter, enough lighter to be noticed and there was almost none of the muzzle blast that H110 produces. Using classic calculations of recoil (per SAAMI) the 800-X load should have produce about 3.7% less recoil impulse and about 7.3% less free recoil energy than the H110 load. In reality that small reduction in actual recoil and the near elimination of the H110 muzzle blast made that feel even bigger than the numbers would indicate.

 

[Erief0g]

Powders and recoil: https://www.ssusa.org/articles/2017/6/19/gunpowder-selection-for-controlling-recoil

Bullet type can also affect recoil because they require different amounts to reach the same velocity. In general, jacketed bullets require more powder to reach the same speed as lead bullets, so jacketed bullets produce more recoil than lead for the same velocity.

Interesting read, learned something today. Thanks

 

[fxvr5]

Interesting read, learned something today. Thanks

You're welcome.

 

[Gary Wells]

I would bet that SNS coating is quite hard if it were to be compared to bare lead.
Different powders due to the reasons quoted above.
different bullet materials such as soft lead compared to hard materials, but I think that this is a maybe.
Possibly amount of the contact surface area of different bullet shapes,
Just my thoughts.

 

[fxvr5]

I would bet that SNS coating is quite hard if it were to be compared to bare lead.
Different powders due to the reasons quoted above.
different bullet materials such as soft lead compared to hard materials, but I think that this is a maybe.
Possibly amount of the contact surface area of different bullet shapes,
Just my thoughts.

Not sure what SNS coating is. Are you referring to the polymer coating on SNS bullets? If so, polymer coated bullets run, on average, a few fps slower than plain lead. https://www.ssusa.org/articles/2017/3/7/coated-bullets-the-future-of-lead-bullets-for-handloaders/

There is a clear difference in speed from lead bullets and jacketed bullets with the same powder charge. Jacketed bullets are slower, and require more powder to reach the same speed as lead bullets.

 

[murf]

Incorrect. See the link posted in #3 above.

went to the jmb link and calculated recoil energy for a 158 grain bullet with 9.0 grains of powder @ 1000 fps with a 2.5 lb. gun. total recoil energy is 5.1 foot pounds. your referenced study shows 3.04 foot pounds for the 9.0 grain powder charge.

the powder portion of the recoil is too small to detect. i inputted .1 pounds for the gun weight (trying to get as close to zero as possible) and got 127.2 foot pounds of recoil energy. three divided by one hundred twenty seven equals two point four percent.

i don't think i can detect a 13 percent of a 2.4 percent change in recoil energy (.3%).

let me know if i'm missing something here. until then i'm sticking with my original opinion.

luck,

murf

 

[murf]

Not sure what SNS coating is. Are you referring to the polymer coating on SNS bullets? If so, polymer coated bullets run, on average, a few fps slower than plain lead. https://www.ssusa.org/articles/2017/3/7/coated-bullets-the-future-of-lead-bullets-for-handloaders/

There is a clear difference in speed from lead bullets and jacketed bullets with the same powder charge. Jacketed bullets are slower, and require more powder to reach the same speed as lead bullets.

same answer in post #11 refutes this claim, too.

murf

 

[fxvr5]

went to the jmb link and calculated recoil energy for a 158 grain bullet with 9.0 grains of powder @ 1000 fps with a 2.5 lb. gun. total recoil energy is 5.1 foot pounds. your referenced study shows 3.04 foot pounds for the 9.0 grain powder charge.

the powder portion of the recoil is too small to detect. i inputted .1 pounds for the gun weight (trying to get as close to zero as possible) and got 127.2 foot pounds of recoil energy. three divided by one hundred twenty seven equals two point four percent.

i don't think i can detect a 13 percent of a 2.4 percent change in recoil energy (.3%).

let me know if i'm missing something here. until then i'm sticking with my original opinion.

luck,

murf

Yeah, I think you're missing something.

The load in the link provided was Sierra 9mm Luger load data with a 125/130 grain bullet for 1000 fps. That's a whole lot different than your 158 grain bullet. Or do you not understand that?

Your reasons for your calculations are confusing. I suspect you're confused. If you want to know how much gunpowder contributes to recoil force, use zero, or close to it, for the gunpowder weight, not the gun weight.

The comparison is how much difference there is in recoil force when using powders that require different amounts of weight to push the same bullet to the same speed in the same gun. The load data at that link found a 13% difference in recoil force between the powder that used 3.7 grains (Titegroup) and the powder that used 9.0 grains (Accurate #9). Calculations based on a 2 lb gun.

People can detect a 13% difference in recoil force. Maybe you can't, but I can.

 

[fxvr5]

same answer in post #11 refutes this claim, too.

murf

Man, are you confused!

 

[Gary Wells]

Not sure what SNS coating is. Are you referring to the polymer coating on SNS bullets? If so, polymer coated bullets run, on average, a few fps slower than plain lead. https://www.ssusa.org/articles/2017/3/7/coated-bullets-the-future-of-lead-bullets-for-handloaders/

There is a clear difference in speed from lead bullets and jacketed bullets with the same powder charge. Jacketed bullets are slower, and require more powder to reach the same speed as lead bullets.

I'm pretty sure that's what I said and your statement about SNS coated bullets verifies that under same or similar conditions SNS coated bullets cause a tad more friction, thus slowing down the bullet a tad.

 

[murf]

The load in the link provided was Sierra 9mm Luger load data with a 125/130 grain bullet for 1000 fps. That's a whole lot different than your 158 grain bullet. Or do you not understand that?

doesn't matter what load, the study is about powder only. the load could be any bullet fired from any pistol.

murf

 

[murf]

Your reasons for your calculations are confusing. I suspect you're confused. If you want to know how much gunpowder contributes to recoil force, use zero, or close to it, for the gunpowder weight, not the gun weight.

no, you use zero for the gunpowder weight and refute my claim.

murf

 

[murf]

The comparison is how much difference there is in recoil force when using powders that require different amounts of weight to push the same bullet to the same speed in the same gun. The load data at that link found a 13% difference in recoil force between the powder that used 3.7 grains (Titegroup) and the powder that used 9.0 grains (Accurate #9). Calculations based on a 2 lb gun.

no, the study shows the difference in force among the listed powders. there is no way three grains of powder has three pounds feet of recoil energy. the whole load only has five!

murf

 

[murf]

People can detect a 13% difference in recoil force. Maybe you can't, but I can.

only way is to solve our difference of opinion is to load up a three grain load and a nine grain load and do a blind test.

let us know how that works out.

luck,

murf

 

[Dudedog]

I think they compute the energy from the powder with the powder exiting the muzzle at a much higher velocity than the bullet. (I can't remember the number I saw someplace but it was way fast like 25000 fps for exiting powder gasses)
Different people feel recoil different, for me for example a load with 4.5 gr of WSF and 125 in 9mm feels softer than a 4gr charge of a faster powder.
Yes according to the math it has more recoil, but the recoil feels softer to me, more of a push less of a snap.
In MCBsexample it was 14gr of 800x vs 23.5 of H110, large difference in the charge weight so I can see the charge weight making a difference in recoil.
In my example in 9mm it looks like the .5gr of powder only makes a .04 ft/lb increase in recoil. I can feel the difference between the two loads and heavier charge of slower powder feels softer. to me a least)
To feel the difference between loads with a 124 in 9mm with the same powder it takes somewhere around 25-30 fps for me to feel the vel difference with a load running about 1020fps so I can feel far less than 13%.
Different people are different so other may be able to detect less or need more to feel it.

 

[WrongHanded]

Okay, so at a given velocity, the faster burning powder will have a lower charge weight and so produce less recoil than a slower burning powder which needs a higher charge weight?

If that's true, what kind of powder can DT possibly be using that would create higher velocities than reloading manuals give with the slower burning powders, but still be below max SAAMI pressure?

For example: if I used H110, it should produce more recoil than 2400 for a given velocity (or just book max), because it's a slower burning powder and therefore the charge weight is higher for the same max pressure. So for this DT load to get higher velocities than anything in the book, but have lighter recoil than even my load, it would have to be using a faster burning powder. But then it'd be over pressure, wouldn't it?

Seems like the only way to know for sure would be (as @Bat Rastard said) to chrono both loads and confirm velocities of both. However, I was under the impression that a few feet of distance (minimum) was needed between the gun and the chronograph, and that's not going to be an option at my local range.

 

[fxvr5]

I think they compute the energy from the powder with the powder exiting the muzzle at a much higher velocity than the bullet. (I can't remember the number I saw someplace but it was way fast like 25000 fps for exiting powder gasses)

SAAMI uses numbers that the gas exits the muzzle from between 1.25 to 1.75 times faster than the bullet.

 

[Rule3]

Without any data from the OP original post the whole discussion is just "theory"

He did not chronograph the velocity, so who the heck knows. it is all speculation.??

Plus there is actual recoil and felt or perceived recoil. The OP "felt" something.

Yes the physics show the weight of the powder in the calculation, but if there is only say a few grains of powder difference fast vs slower) no one is going to feel 3 to 5 grains of powder every thing else equal (including velocity)

Gazillions of threads on the web about this fast vs slow powder, without DATA there is nothing.

More popcorn please

 

[ATLDave]

nope, just velocity.

murf, there's a lot of data out there to the contrary. See, e.g., http://www.shootingtimes.com/editorial/measure-relative-handgun-recoil/99442

As mcb mentioned, the weight of powder punches above its weight because the gasses that the powder turns into are generally of significantly higher velocity than the projectile. So they contribute more to the recoil than the difference in their weight.

Here's an excerpt of that article showing what was measured by tracking the movement of a ransom rest arm by various loads from the same gun. Note that, at any given point along the horizontal access, velocity is the same. The projectiles were the same. The gun was the same. The only difference is the type and amount of powder used to achieve the velocities.



As you can see, if you compare a mid-slow powder like HS6 to an faster powder like N320, you get equivalent recoil (the vertical axis) at velocities that are ~75-100 fps apart.

Throw in the blast/flash that most people process as being recoil, and it starts to make a BIG difference.

 

[Toprudder]

If the weight of the powder does not matter, then it would be really hard to explain how a compensator or muzzle brake works.