Heavy for Caliber Rounds
- Thread starter dts686
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Brian Pfleuger
Moderator Emeritus
There's no hard and fast (or slow) rules for handgun or rifles.
Slow and heavy has less recoil? Slow and light would have less yet.
Recoil is a function of momentum. The starting momentum of the system is zero. The final momentum after the bullet exits the muzzle must also be zero. The bullet has momentum traveling "forward" so the gun must have the exact same momentum traveling "backwards" such that the sum is zero.
Which ever bullet and powder combination has less total momentum will be the combination that has less recoil. It doesn't matter what kind of gun it is.
Slow and heavy has less recoil? Slow and light would have less yet.
Recoil is a function of momentum. The starting momentum of the system is zero. The final momentum after the bullet exits the muzzle must also be zero. The bullet has momentum traveling "forward" so the gun must have the exact same momentum traveling "backwards" such that the sum is zero.
Which ever bullet and powder combination has less total momentum will be the combination that has less recoil. It doesn't matter what kind of gun it is.
I think what you're referring to isn't actually recoil, but recoil velocity. The heavier rounds tend to have less recoil velocity, because of the lowered velocity. A hot 240 grain .44 and a hot 300 grain .44 out of my dad's Taurus exhibit this felt recoil phenomenon. It was the same powder, same bullet manufacturer, etc. You get a push instead of a snap.
In my experience, this can get negated with the velocities from rifle cartridges. Once you start putting heavy bullets in at their standard respective velocities, you get more felt recoil because the recoil velocity is still high enough to pop you, but you get a heavier total weight moving out of the bore as well. You don't get that trade-off.
Case capacity has a lot to do with it as well. In pistol cartridges, bigger bullets take up more powder space than smaller bullets, once you start loading with case-filling powders. If you're not using case-filling powders in your rifle, you may be able to get a higher charge with the heavier bullet than if you were using a straight case. This "theory" is also based on published data. I'm not saying to cram more powder in just because it fits.
As you can see, there are a multitude of factors that go into felt recoil. If two powders are loaded to the same velocity in a given round, but 1 is 25% heavier than the other, the heavier charge weight will recoil more, because there is more mass leaving the barrel. You'll also likely get more muzzle blast and flash, given that powders that require more weight per velocity are usually the slower burners. That's not always true either.
The bullet weight is far from the only factor in recoil. You didn't state if you are a hand loader or if you are buying factory ammunition. To build on Brian's point, there's usually a reason that reduced recoil rifle ammunition is not offered in the heavy-weight bullets for a given caliber. It's easier to make a lighter bullet kick less than a heavy bullet. It's also easier to get a lighter bullet to expand properly at lower velocities than a heavier bullet. The engineering challenges are easier.
In my experience, this can get negated with the velocities from rifle cartridges. Once you start putting heavy bullets in at their standard respective velocities, you get more felt recoil because the recoil velocity is still high enough to pop you, but you get a heavier total weight moving out of the bore as well. You don't get that trade-off.
Case capacity has a lot to do with it as well. In pistol cartridges, bigger bullets take up more powder space than smaller bullets, once you start loading with case-filling powders. If you're not using case-filling powders in your rifle, you may be able to get a higher charge with the heavier bullet than if you were using a straight case. This "theory" is also based on published data. I'm not saying to cram more powder in just because it fits.
As you can see, there are a multitude of factors that go into felt recoil. If two powders are loaded to the same velocity in a given round, but 1 is 25% heavier than the other, the heavier charge weight will recoil more, because there is more mass leaving the barrel. You'll also likely get more muzzle blast and flash, given that powders that require more weight per velocity are usually the slower burners. That's not always true either.
The bullet weight is far from the only factor in recoil. You didn't state if you are a hand loader or if you are buying factory ammunition. To build on Brian's point, there's usually a reason that reduced recoil rifle ammunition is not offered in the heavy-weight bullets for a given caliber. It's easier to make a lighter bullet kick less than a heavy bullet. It's also easier to get a lighter bullet to expand properly at lower velocities than a heavier bullet. The engineering challenges are easier.
Recoil has both energy (one half mass times velocity squared) and acceleration (change in velocity over time).
Things that spread the energy out over time help reduce felt recoil. Things that spread the acceleration over time (like increasing mass) tend to help reduce felt recoil.
That is why people talk about "push" and "slap" feeling, you can expend the same energy, but if you spread it out over more time you get more of a "push" feel.
Another part of recoil is the hot gasses escaping after the bullet. I've had folks tell me that the hot gasses do not contribute to recoil, but when I ask them to explain to me how hot gasses push a rocket they usually scratch their head. It is the same thing, just because gasses aren't solid doesn't mean they don't have mass, so sometimes switching between powders can help reduce recoil. For example if Powder A achieves the same velocity as Powder B, but with half the amount in grains, you would expect the load with Powder A to have less recoil, although not by very much because the amount of total mass leaving the barrel will only be reduced by half the amount of powder, which in a pistol pushing heavy bullets is a very small amount indead compared to the bullet.
Jimro
Things that spread the energy out over time help reduce felt recoil. Things that spread the acceleration over time (like increasing mass) tend to help reduce felt recoil.
That is why people talk about "push" and "slap" feeling, you can expend the same energy, but if you spread it out over more time you get more of a "push" feel.
Another part of recoil is the hot gasses escaping after the bullet. I've had folks tell me that the hot gasses do not contribute to recoil, but when I ask them to explain to me how hot gasses push a rocket they usually scratch their head. It is the same thing, just because gasses aren't solid doesn't mean they don't have mass, so sometimes switching between powders can help reduce recoil. For example if Powder A achieves the same velocity as Powder B, but with half the amount in grains, you would expect the load with Powder A to have less recoil, although not by very much because the amount of total mass leaving the barrel will only be reduced by half the amount of powder, which in a pistol pushing heavy bullets is a very small amount indead compared to the bullet.
Jimro
Brian Pfleuger
Moderator Emeritus
Jimro said:
And the truth is that the "gas after-effect" can be a significant portion of felt recoil. The closer the powder charge weight is to the bullet weight, the bigger portion of recoil comes from the gas after-effect. Not only does some percentage of the powder get accelerated (as gas mostly) along with the bullet but when the bullet "uncorks" the barrel, the gas accelerates to a very, very high speed, it actually passes the bullet.
For instance, I have a load for .22-250 that uses 41.5gr of powder under a 35gr bullet. The gas after-effect is considerably more of the recoil than is the bullet.
Also, while recoil certainly has kinetic energy, it is not actually a product of KE, so that number can be misleading. As an extreme example, a 32gr bullet at 4,600fps has the same kinetic energy as a 200gr bullet at 1840fps but that 200gr bullet has 2.5 times as much momentum and (all else being equal) would produce 2.7 times as much free recoil energy and 2.5 times as recoil velocity. On the other hand, the 32gr bullet would apply it's entire recoil impulse in about 1/3 the time.
Recoil can be calculated by using a math formula if you know these 4 things
The weight of the firearm
The weight of the projectile
The weight of the powder charge
The Velocity of the projectile.
Plug them in here
http://www.handloads.com/calc/recoil.asp
The results are often surprising. Sometimes big and slow recoils more than small and fast, sometimes the other way.
The wildcard that people often never consider is that the powder charge weight which must be added to the projectile weight. If 2 different chambering's shoot 165 gr bullets to the same speed, but if one needs 10 gr more powder to do it, you get the recoil comparable to a 10 gr heavier bullet at the same speed with the gun needing more powder. That can make a significant difference.
3-4 oz difference in a guns weight can make a considerable difference as well.
The weight of the firearm
The weight of the projectile
The weight of the powder charge
The Velocity of the projectile.
Plug them in here
http://www.handloads.com/calc/recoil.asp
The results are often surprising. Sometimes big and slow recoils more than small and fast, sometimes the other way.
The wildcard that people often never consider is that the powder charge weight which must be added to the projectile weight. If 2 different chambering's shoot 165 gr bullets to the same speed, but if one needs 10 gr more powder to do it, you get the recoil comparable to a 10 gr heavier bullet at the same speed with the gun needing more powder. That can make a significant difference.
3-4 oz difference in a guns weight can make a considerable difference as well.
Brian Pfleuger
Moderator Emeritus
The powder charge portion gets complicated, as it is influenced by the portion of the powder that follows the bullet down the barrel and also by the muzzle pressure.
I use that recoil calculator you link to quite regularly, for quick reference or when I don't have QuickLoad handy but I bet that QuickLoad does a more complete analysis.
I suspect that the calculator in that link either uses 100% of the charge weight or some fixed proportion, where QuickLoad adjusts the ratio depending on the "over-bore" of the cartridge, using a variable called Weighting Factor.
I'll have to do some comparisons when I get a chance.
I use that recoil calculator you link to quite regularly, for quick reference or when I don't have QuickLoad handy but I bet that QuickLoad does a more complete analysis.
I suspect that the calculator in that link either uses 100% of the charge weight or some fixed proportion, where QuickLoad adjusts the ratio depending on the "over-bore" of the cartridge, using a variable called Weighting Factor.
I'll have to do some comparisons when I get a chance.
jersurf101
New member
I truly believe that muzzle blast in a handgun will contribute to recoil perceived by the shooter. I use the example of loading .40sw in the same grain weight bullet Blue Dot vs Unique. The Blue dot appears to me to have more recoil whether it is just the muzzle blast or not I couldn't prove. So I so think the type of powder used makes a difference.
Heavier projectiles recoil more all most all of the time.
Heavier projectiles recoil more all most all of the time.
dts686 said:
The heavier the projectile, the heavier the felt recoil - consider Sir Isaac Newton's Third law of Motion:
"For every action, there is an opposite and equal reaction".
Handgun rounds are generally less powerful than rifle rounds.
( A .44 Magnum round, fired in a rifle, is still a pistol round.)
Given the same cartridge, different rifles may have different felt recoil, due to differences in both rifle weight, and stock shape/ergonomics.
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Unlicensed Dremel
Moderator
What jmr40 said! Use that calculator and it will begin to make sense to you.
Brian Pfleuger
Moderator Emeritus
Here's an example from hot .44mag loads in an 8" barrel, output from QuickLoad and the handloads.com recoil calculator. You can see that they agree fairly well but not exactly. QuickLoad also gives momentum, in addition to velocity and energy. These loads use the same powder, the only difference is charge weight and the bullet. You can see that the "gas after-effect" contributes about 1/3rd of total recoil. I'll do one for rifles later, if anyone besides me cares.
200gr SPeer GD, 1793fps
300gr XTP, 1398fps
200gr SPeer GD, 1793fps
300gr XTP, 1398fps
Attachments
I'm shooting a muzzle loader -a rifled musket- with conicals that weigh 730 grains ( almost 1 3/4 ounces) at only 900 fp/s and it recoils so hard it makes me feel dizzy after two dozen shots. The 300WM loaded with 200 grainers with almost 3 1/2 times the muzzle velocity is a pussycat to shoot.