Delaware_Dan
New member
Help me win a bet here, do heavier bullets recoil more or less?
Do heavier bullets mean more or less recoil?
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Magnum Wheel Man
New member
depends... heavier bullets at the same velocity as a lighter bullet will always have more recoil...
however, often the cartridge pressures go too high to get equal velcities, & often if you equalize the cartridge pressures, the heavier bullet actually has less recoil... this effect is even more pronounced, the bigger the bore size
however, often the cartridge pressures go too high to get equal velcities, & often if you equalize the cartridge pressures, the heavier bullet actually has less recoil... this effect is even more pronounced, the bigger the bore size
Brian Pfleuger
Moderator Emeritus
That gets complicated.
Depends on factors like acceleration (barrel length and powder charge) also.
A bullet that is 125gr and leaves a 3 inch barrel at 800fps would have a sharper perceived recoil than the same bullet at the same speed leaving an 8 inch barrel. Now, whether or not you could actually tell the difference is another matter.
Depends on factors like acceleration (barrel length and powder charge) also.
A bullet that is 125gr and leaves a 3 inch barrel at 800fps would have a sharper perceived recoil than the same bullet at the same speed leaving an 8 inch barrel. Now, whether or not you could actually tell the difference is another matter.
A rather rare case since heavier bullets can rarely be driven to the same velocity as lighter bullets.
The recoil momentum available is bullet weight times muzzle velocity.
So 200 grains at 1000 ft/s is the same 300 grains at 667 ft/s.
How it feels (sharp, push, etc.) are the items of 'felt recoil.'
Bore axis above grip, grip style, barrel dwell, and many other factors all effect how it feels to the shooter.
F=ma, High School Physics redux
Force (recoil) = mass multiplied by acceleration. If acceleration is kept constant, as roughly estimated by constant muzzle velocity, and the same firearm is used then force is dependent on mass. Therefore, recoil is greater with a larger mass bullet than a lesser mass bullet.
Force (recoil) = mass multiplied by acceleration. If acceleration is kept constant, as roughly estimated by constant muzzle velocity, and the same firearm is used then force is dependent on mass. Therefore, recoil is greater with a larger mass bullet than a lesser mass bullet.
Hollywood physics
As most of us know, Hollywood is not oriented to any kind of physics in many of its action movies. This means that the shooter of any weapon capable of throwing the target individual back should also be thrown in the opposite direction with almost equal force. It is still F=ma.
As most of us know, Hollywood is not oriented to any kind of physics in many of its action movies. This means that the shooter of any weapon capable of throwing the target individual back should also be thrown in the opposite direction with almost equal force. It is still F=ma.
recoil
"A rather rare case since heavier bullets can rarely be driven to the same velocity as lighter bullets"
I beg to differ, at least with the "rarely" part. It may well be true at maximum velocity/loads for different bullets but there's a whole spectrum of common velocities below max. It's fairly easy, for example, to load both 185 and a 230 grain .45 slug to 800 fps.
Pete
"A rather rare case since heavier bullets can rarely be driven to the same velocity as lighter bullets"
I beg to differ, at least with the "rarely" part. It may well be true at maximum velocity/loads for different bullets but there's a whole spectrum of common velocities below max. It's fairly easy, for example, to load both 185 and a 230 grain .45 slug to 800 fps.
Pete
Brian Pfleuger
Moderator Emeritus
It's not *really* related to length. It actually has to do with the powder. A faster burning powder is needed to drive a bullet to the same speed in a shorter barrel. The recoil will be "faster" because of that burn speed. In a longer barrel the same powder and charge would *mostly* feel the same but might actually produce a lower speed because the charge could "burn out" before the bullet leaves the barrel. So... you might need a slower burning powder to produce the same fps to be sure that the bullet gets a good "push" all the way down the barrel.
Notice all the qualifiers like "might" and "could"
In the real world you'd be hard pressed to feel the difference, mostly.
Recoil is acceleration of the gun rearward to a certain level of recoil energy, which what your nerve endings notice. Newton's equal and opposite reaction force accelerates the gun rearward while accelerating the bullet forward. The forces are the same, but the lighter bullet accelerates more. If you could get the size and weight of the gun down to the sized and weight of the bullet, the shooter would be hurt as much as the shootee. Once the bullet clears the muzzle the remaining pressure in the barrel then accelerates all the propelent gases and unburned powder forward which acts as a rocket, adding still more recoil to the gun.
The balance, as the other said, is tricky. If you put the same amount of the same powder behind both a light and a heavy bullet, the heavy bullet will generally produce more recoil energy because it takes longer to leave the barrel and so lets the propellant gases push on it longer which adds to gun acceleration rearward. This bullet will have higher ballistic efficiency because that will have translated more of the propellant energy into bullet energy than happened with the lighter bullet.
But reality is messier. The bigger bullet doesn't allow as much powder, and what it does allow, if it is slow powder, will burn more completely in the bore, making less rocket effect at the end. Both those factors tend to reduce recoil, while the longer bullet barrel time produces more. So there isn't a simple linear relationship. In general, with typical factory loads of the same brand, heavier bullets recoil more. But there are exceptions.
The balance, as the other said, is tricky. If you put the same amount of the same powder behind both a light and a heavy bullet, the heavy bullet will generally produce more recoil energy because it takes longer to leave the barrel and so lets the propellant gases push on it longer which adds to gun acceleration rearward. This bullet will have higher ballistic efficiency because that will have translated more of the propellant energy into bullet energy than happened with the lighter bullet.
But reality is messier. The bigger bullet doesn't allow as much powder, and what it does allow, if it is slow powder, will burn more completely in the bore, making less rocket effect at the end. Both those factors tend to reduce recoil, while the longer bullet barrel time produces more. So there isn't a simple linear relationship. In general, with typical factory loads of the same brand, heavier bullets recoil more. But there are exceptions.
Delaware_Dan
New member
Same gun, (gp100) 125 grn. and 158 grn. To me the lighter load has more of a muzzle flip, and the heavier load has more of the "push".
Brian Pfleuger
Moderator Emeritus
You might also check here for an actual calculator for these sorts of things.
http://www.eskimo.com/~jbm/calculations/recoil/recoil.html
The number doesn't always translate well into how it actually "feels" but it makes for a good theoretical comparison.
http://www.eskimo.com/~jbm/calculations/recoil/recoil.html
The number doesn't always translate well into how it actually "feels" but it makes for a good theoretical comparison.
+1-The lighter bullet load has a higher recoil velocity, which "feels" like a harder kick, since it comes back at the shooter quicker. The heavier bullet actually takes more effort on the part of the expanding gasses to get it moving down the bbl. Therefore the gasses are pushing back on the gun harder than they do with a lighter bullet. It's not really a matter of how long the bullet is in the bbl. since they both leave the bbl. in milliseconds. It's how hard the gasses have to work to do their job.Delaware_Dan said:
The lighter bullet load recoils faster because as we all learned in school, "For every action, there is an equal and opposite reaction."
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I've posted on this before, and I do believe recoil is dependent on barrel length, where, surprisingly enough, (and all else being equal), a longer barrel increases recoil. Simple physics says it has to be so.
First, a couple of qualifiers: I'm talking about the relatively small distance the gun moves while the bullet's still in the barrel - not the perceived recoil.
When solving the Conservation of Momentum equation, the MxV of the gun equals the MxV of the bullet (and powder charge). Velocity is distance/time. Distance the bullet travels is barrel length, and the distance the gun moves is this "intrinsic recoil" I'm referring to. The time the bullet spends in the barrel is the same as the time the gun gets pushed upon, i.e. recoils, so time cancels out. What you're left with is that the distance the gun recoils is proportionate to the barrel length and the relative masses of the bullet & gun.
I suspect shorter barreled guns probably seem to recoil more because they're lighter (and therefore will recoil more) and because the perceived recoil (strength of impulse and muzzle blast) is greater.
In the end, I do agree here.
Brian Pfleuger
Moderator Emeritus
I agree. My example though is one of trying to make the bullet exit a longer barrel at the same velocity. Your example (if I'm reading correctly) applies to identical rounds which should theoretically leave different length barrels at different speeds. Although, once again in the real world its matters to the extent of 50 fps or something equally meaningless.
I think I agree with that also
. Which means, all else being equal, smaller bullets must produce less recoil.recoil is a product of the collision that takes place between the bullet and your gun.
a smaller gun for a bullet of a given size will generally have more recoil.
likewise a larger bullet for a gun of a given size will generally have more recoil.
There are other factors that come into play as well such as the amount of energy stored in the propellant. This is basically as follows:
A faster moving bullet for a bullet and gun of a given size, will produce more recoil.
Then there are more complicated bits like... the rate at which the powder burns (and accelerates the projectile), gives a sharp jolt versus a squishy push feeling, and weapons that have bolts and slides generally have less recoil because the spring absorbs some of the shock.
and when i say larger in terms of gun and bullet size, it really comes down to the mass (or weight) of the objects. a long narrow rifle bullet may be light in comparison to a large pistol round but it moves much faster, resulting in a more energetic collision.
Its like when a speeding truck smashes into a small car. The heavier object always has less percieved "recoil". Of course then you get into more complications with that analogy, since cars these days are designed to crumple like a paper airplane, which absorbs energy in a similar manner to a spring loaded bolt/slide on a weapon.
a smaller gun for a bullet of a given size will generally have more recoil.
likewise a larger bullet for a gun of a given size will generally have more recoil.
There are other factors that come into play as well such as the amount of energy stored in the propellant. This is basically as follows:
A faster moving bullet for a bullet and gun of a given size, will produce more recoil.
Then there are more complicated bits like... the rate at which the powder burns (and accelerates the projectile), gives a sharp jolt versus a squishy push feeling, and weapons that have bolts and slides generally have less recoil because the spring absorbs some of the shock.
and when i say larger in terms of gun and bullet size, it really comes down to the mass (or weight) of the objects. a long narrow rifle bullet may be light in comparison to a large pistol round but it moves much faster, resulting in a more energetic collision.
Its like when a speeding truck smashes into a small car. The heavier object always has less percieved "recoil". Of course then you get into more complications with that analogy, since cars these days are designed to crumple like a paper airplane, which absorbs energy in a similar manner to a spring loaded bolt/slide on a weapon.
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