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weight... light and fast or heavy and slow?


Guest oldslowchevy

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Guest oldslowchevy

what is better for a revolver as far as recoil, a light fast bullet or a heavy slow bullet?

oh yeah and why?

we are talking medium calibers 32 38 41 ect.. no magnums though.

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Physics is still Physics...

lots of variables,.. weight of firearm( mass), height of bore above center-line and barrel length(leverage), powder used, bullet composition etc.

Muzzle energy is force light bullets tend to be more of a snap and heavy more of a push for a given ME ( rate of acceleration )

Also depends on how the shooter perceives it I am sure there are recoil formulas somewhere on the WWW

I have never been one for recoil figuring I just load the bullet I need to get the job done and figure recoil is the price to pay for the ride...and the fun is in handloading a balance between the performance on both ends..

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Velocity increases energy by a factor of 4 while weight doesn't.

Doubling the bullet weight only doubles the energy while doubling velocity increases energy by a factor of 4. And the same amount of energy is going to recoil the same regardless of the bullet weight.

A 7.62x25 Tokarev with a 85 grain bullet at 1450 fps has the same energy as a 230 grain bullet travelling at 881 fps. Even though the energy is the same the recoil impulses are going to be drastically different because of the velocity. The 1450 fps is over more quickly than the 881 fps so the 1450 is going to feel snappeir than the 881. The recoil energy is the same but the difference is the amount of time it takes.

I think the reason why most people think a heavier bullet recoils harder is because it spreads its recoil pulse out over a longer timeframe. It is perceived as a heavier recoil because of the longer recoil impulse.

Dolomite

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Every action has an opposite reaction. force is mass X acceleration. Energy is mass X velocity squared. Momentum is mass X velocity. All that says the same thing: the faster it goes and the heavier it is and the faster it accelerates from 0 to muzzle exit, the more F/E/P it will have (p is momentum, for some unholy reason, by convention). THe higher ANY of those 3 values is (F/P/E) the more recoil your gun will have --- that is how much "oomph" (to be really scientific) is put into accelerating your gun from zero to its maximum velocity backwards, and that is related to how much force you must exert to stop the gun. But that is just a number that represents how much the gun is going to be pushed, how the gun behaves is going to vary depending on its weight, length, grip width, and a number of factors. For an extreme example, if your gun weighs as much as the bullet, it is going to try to move as fast as the bullet does from recoil (!!!). If your gun weighs enough (say, 300 pounds), it may not move at all (gravity, inertia, and friction could be larger than the force of the explosion trying to move it, for example, if you fire your pistol in your car in neutral, it will not make the car roll backwards). All that to say, if you want a gentle gun, start by getting a larger, heavier, fat & comfortable grip gun in a non-magnum caliber. Get a large 357 and shoot 38s in it, or a big 44 and shoot 44sp in it, or an older, larger 32, or the like. Avoid the aluminum framed snubbies and anything with tiny "girl grips" (think the classic S&W lady smith grips) in favor of some wide (and probably rubber) grips. Get a long barrel, 6+ inches. Maybe try a ported barrel.

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I was trying to provide the why. The why is just the physics I gave --- any way you want to measure recoil or bullet power, it all boils down to mass and velocity or a cousin of those (acceleration is related to velocity). Any increase in mass or velocity or acceleration means more recoil, because an increase in those makes the bullet more powerful, and the equal opposite reaction makes the recoil more powerful --- all things being equal. Since guns vary, however, the same cartridge with the same mass and velocity can make different guns push against the human in different ways, which changes how recoil feels (even if the numeric values are the same). Hopefully this is enough, but without at least high school level physics, it is difficult to follow. If you had that much, hopefully I jarred some memories.

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Velocity increases energy by a factor of 4 while weight doesn't.

Doubling the bullet weight only doubles the energy while doubling velocity increases energy by a factor of 4. And the same amount of energy is going to recoil the same regardless of the bullet weight.

A 7.62x25 Tokarev with a 85 grain bullet at 1450 fps has the same energy as a 230 grain bullet travelling at 881 fps. Even though the energy is the same the recoil impulses are going to be drastically different because of the velocity. The 1450 fps is over more quickly than the 881 fps so the 1450 is going to feel snappeir than the 881. The recoil energy is the same but the difference is the amount of time it takes.

I think the reason why most people think a heavier bullet recoils harder is because it spreads its recoil pulse out over a longer timeframe. It is perceived as a heavier recoil because of the longer recoil impulse.

Dolomite

This is an explanation I can wrap my head around.

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Guest Lester Weevils
Every action has an opposite reaction. force is mass X acceleration. Energy is mass X velocity squared. Momentum is mass X velocity. All that says the same thing: the faster it goes and the heavier it is and the faster it accelerates from 0 to muzzle exit, the more F/E/P it will have (p is momentum, for some unholy reason, by convention). THe higher ANY of those 3 values is (F/P/E) the more recoil your gun will have --- that is how much "oomph" (to be really scientific) is put into accelerating your gun from zero to its maximum velocity backwards, and that is related to how much force you must exert to stop the gun.

Yep, and as Dolomite noted, the amount of time that the "oomph" is spread out? Ferinstance some of the laser fusion experiments supposedly deliver enough energy to run a city, but they only deliver that energy for a femptosecond, focused on a microscopic target. If you spread the time and enlarge the target it wouldn't do much.

Given a hypothetical gun with equivalent weight and muzzle energy as a 44 mag snubbie, but able to linearly accelerate the bullet over 100 milliseconds, then it would likely have trivial recoil?

There are so many factors, but muzzle energy being equal, wouldn't one expect a heavier bullet to "stretch" the recoil pulse over a longer time duration? It would involve matching powder burn rate against bullet weight and barrel length to attempt as "linear" acceleration possible over the length of the barrel?

I would have expected that the slow heavy bullet would have less-noticeable subjective recoil than a fast light bullet (at the same muzzle energy), but Dolomite says it may be the opposite, and Dolomite has infinitely more hands-on experience.

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Well, when it comes to explaining physics it is all Greek to me. However, Since I have been reloading and shooting 32 years I still have an opinion. Look at a 38 for example. You load a 125 grain bullet with 5.3 grains of WW 231 for a 1000 fps and 19800 CUPS or you load 158 grain bullet with 4.7 grains of WW 231 for 825 fps and the same pressure range. The way I have always looked at it is the total of bullet weight and charge weight with equal pressure, the heavier load will have more felt recoil. in this case you either pushing 133.3 grains or 162.7 grains...which one is heavier? All the charts I have ever seen in books and magazines seem to coincide with my findings. I can really tell the difference in my 45-70 or 458. Dramatic difference between light bullets and heavy bullets, even in low velocity loads. So if you want lighter recoil, go for standard velocity loads with lighter bullets. IMHO.

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Glockster is right

The momentum of the recoil is equal to the momentum of the bullet M * V = - m * v

It means M * Er = m * Eb Which means the ratio of the recoil energy to the bullet energy Er / Eb = m / M equal to the ratio of the mass of the bullet to the mass of the gun.

For given muzzle energy the recoil is reversely proportional the the mass of the bullet

It is not intuitive. So rent and try FN 57. You can barely feel the recoil

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Yep, and as Dolomite noted, the amount of time that the "oomph" is spread out? Ferinstance some of the laser fusion experiments supposedly deliver enough energy to run a city, but they only deliver that energy for a femptosecond, focused on a microscopic target. If you spread the time and enlarge the target it wouldn't do much.

Given a hypothetical gun with equivalent weight and muzzle energy as a 44 mag snubbie, but able to linearly accelerate the bullet over 100 milliseconds, then it would likely have trivial recoil?

There are so many factors, but muzzle energy being equal, wouldn't one expect a heavier bullet to "stretch" the recoil pulse over a longer time duration? It would involve matching powder burn rate against bullet weight and barrel length to attempt as "linear" acceleration possible over the length of the barrel?

I would have expected that the slow heavy bullet would have less-noticeable subjective recoil than a fast light bullet (at the same muzzle energy), but Dolomite says it may be the opposite, and Dolomite has infinitely more hands-on experience.

Yes, time matters. If you look at F=MA, A is change in velocity/ change in time (miles / hour for example). If you go to 10 miles per hour in 2 seconds, force multiplier is 5 (times the mass). If you do it in 10 seconds, force is 1. The difference between cartridges in time to accelerate the round is not very much variation, though. You can nearly ignore this factor unless comparing very different rounds such as true black powder rifle vs a .40 pistol round or something drastic.

So yes, a 44 mag that took an insanely long time to go from zero to max velocity would have very low recoil. The longer the time, the lower the recoil --- the same energy and all are expended but your arm is absorbing them over time, rather than all at once.

Energy makes a complex question. Remember that energy is MVV so the velocity is much, much, much more imortant than the mass. A heavier bullet with the same energy cuts the velocity a bit, but even a small change in velocity that is squared is significant changes in energy levels. All things being equal I would think the recoil would be the same, if the momentum and energy and all of the 2 rounds were equal. But to be honest I am not sure without a moment to sit down and do the math, which I do not have right this second. I will go do that tonight or tomorrow.

My gut feeling is that if the energy is the same, the recoil is the same. The gun's EEO does not care what the mass of the bullet was. It cares what the forces used to shove it were. If those forces are the same, then the recoil is the same. However, I am not sure that is the whole of your answer, because changing the mass of the bullet does one thing to momentum and another to energy, and I need that sheet of paper to answer as this type of physics is a little rusty for me.

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A friend of mine has a p229 in .40 s&w with the drop in .357 sig conversion and I asked if the .357 sig had less recoil because the xd40 I carry is a little snappy for my wife and I was thinking about going to .357 sig because of lighter bullet and was told the .357 sig had somewhat

More recoil by my friend. Maybe he was mistaken. Any thoughts on which has less recoil.

Sent from my iPhone using Tapatalk

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Guest Lester Weevils
Yes, time matters. If you look at F=MA, A is change in velocity/ change in time (miles / hour for example). If you go to 10 miles per hour in 2 seconds, force multiplier is 5 (times the mass). If you do it in 10 seconds, force is 1. The difference between cartridges in time to accelerate the round is not very much variation, though. You can nearly ignore this factor unless comparing very different rounds such as true black powder rifle vs a .40 pistol round or something drastic.

So yes, a 44 mag that took an insanely long time to go from zero to max velocity would have very low recoil. The longer the time, the lower the recoil --- the same energy and all are expended but your arm is absorbing them over time, rather than all at once.

Energy makes a complex question. Remember that energy is MVV so the velocity is much, much, much more imortant than the mass. A heavier bullet with the same energy cuts the velocity a bit, but even a small change in velocity that is squared is significant changes in energy levels. All things being equal I would think the recoil would be the same, if the momentum and energy and all of the 2 rounds were equal. But to be honest I am not sure without a moment to sit down and do the math, which I do not have right this second. I will go do that tonight or tomorrow.

My gut feeling is that if the energy is the same, the recoil is the same. The gun's EEO does not care what the mass of the bullet was. It cares what the forces used to shove it were. If those forces are the same, then the recoil is the same. However, I am not sure that is the whole of your answer, because changing the mass of the bullet does one thing to momentum and another to energy, and I need that sheet of paper to answer as this type of physics is a little rusty for me.

Yes interesting problem. Dunno much about it.

For instance, a 1600 gr bullet @ 250 fps, a 400 gr bullet @ 500 fps, a 100 gr bullet @ 1000 fps, or a 25 gr bullet @ 2000 fps ought to all generate about 222 ft-lbs. Given a barrel length of 12", if the powder burn could be adjusted so that the acceleration is roughly linear for the entire traverse thru the barrel (I have no idea if it would be possible), then the recoil pulses ought to be 4 ms, 2 ms, 1 ms, and 0.5 ms.

Given a hypothetical fixed-barrel, fixed-bolt gun capable of firing all those rounds-- They are all pretty short times, so dunno if a person would notice a lot of difference. It might make a mess to get hit by a sharp-nosed 1600 gr projectile even at 250 fps?

To accomplish linear acceleration, wouldn't the pressure behind the bullet need to remain constant up until the bullet exits the barrel? So wouldn't there be additional "terminal recoil" from the gas jet after the bullet leaves the barrel? Wonder how much of the total recoil would be from "rocket thrust" of the gas leaving the barrel?

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Well, if you wanted a simple answer...

G -- mass of gun, x, velocity of gun (and the value in question, really), M, bullet mass, V, bullet velocity...

we know momentum is conserved (basic proven physics law).

So we know GX = MV, G is constant (more or less, you did fire one round of various weights but forget this small amount) so X is also constant if MV is not changed.

The only way to change the recoil is to change MV. Change the mass of the bullet and keep the velocity the same, its going to kick more. Simple answer. But its not that simple because the mass and velocity always change together in real loads, making it a 2 variable system and more difficult to answer. In real loads, it could go either way... I do not know ... it could be that in general that heavier bullets are not dropped in velocity so much, giving a higher MV. Or the reverse could be true. If you want to know, the data exists for anyone who wants to sit there and go over for a couple of days. Not me, though. Its probably safe to say that for a given type and brand of ammo (hunting, defense, plinker, etc) in a particular caliber, different weights have little effect on recoil for most pistols and that the small differences cannot even be felt by most shooters.

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Guest oldslowchevy

belive it or not i really do understand most of the answers given.

let me pose part 2 of my question but it is really more information rather than another question though another question will be asked.

i would like to get a snubby for my wife (looking at the chater arms and taurus) so a .32 .327 .38 .357 .40 is what i am debating on for her.

she is not a shooter though i want her to know how to safely handle the gun and not be afriad of it which then would make it useless if it is ever needed. we own a 22 that she will use to get used to guns (single action revolver). we will be going to the range later this week.

back to the snubby, she is afraid of it kicking out of her hands (she does have very weak hands) she needs light loads to practice with until she gets use to it.

would she be better off with factory ammo or would i be better finding a reloaded near me (one of you guys maybe) to make up light practice rounds no matter what the caliber till i get her used to factory loads?

she may have no trouble at all but i wont know till i get her something. i am think a 357 would be the way to go for self defense but that just may not best choice for practice.

so tring to find what she would be able to handle.

i will know more after we go to the range and shoot our revolvers, her 22(mag...hehehe) and my 45 colt.

i hope this added info helps and please people laymans terms please! as i am not very smart but i can lift heavy things.

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What barrel length in .357 are you looking at? .38 rounds in that should be fairly light respectivley speaking.

I do not know (and doubt) any reloaders will do that for you, they may however invite you over to learn and let you reload some of your own.

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Guest Lester Weevils

I think in general that a semi-auto will recoil less in a given muzzle energy range than a revolver, and blowback semi-auto's will recoil more than moving-barrel semi-auto's.

In addition, light pistols will tend to have more perceived recoil than heavy pistols. And pistols where the barrel axis is lower will have less "snap-back" muzzle rise and possibly less perceived recoil.

A stainless S&W 649 .357 snubbie was the first pistol I got a long time ago. It is a pretty heavy little gun for its size. For a long time the recoil did not feel objectionable and sometimes I'd fire 50 or 100 rds thru it on a range trip. Then about age 61 I took it to the range to make sure it would still go bang and ran 10 self-defense rounds thru it. Felt like my wrist was broken and my wrist hurt the rest of the day, so I went and traded off that snubby the very same saturday. Getting older might make recoil more painful. If your wife is sensitive to recoil maybe a .38 snubbie, and a fairly heavy one, would be the way to go? You can shoot .38 in .357 snubbies of course but if you mostly shoot .38 in a .357 you can't use .357 in the gun any more until you do really thorough cleaning. Gunk builds up preventing .357 rds from going all the way in and it takes a lot of elbow grease to fix that.

I traded the .357 snubbie on a Kahr P9 that is easier to shoot accurately than the snubbie, easier to carry concealed than the snubbie (about the same size and much thinner), and it has trivial felt recoil compared to the snubbie. It doesn't have any more recoil than a full-size Beretta 92 or CZ 85. None of those bother my wrist at all even after getting old. As far as that goes, a full size .357 revolver or a .45 1911 doesn't bother my wrist, but that snubbie was a beast. The other painful-recoil gun I have is a NAA .380 tiny blowback pistol. It is not pleasant to shoot either, though not as bad as the snubbie.

Edited by Lester Weevils
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I would get her a 357 and shoot weak 38s in it. I do not know how widely available they are but I have often found very, very weak 38 target ammo; one of our local stores sells some "factory reloads" or whatever you call them (a vendor who can sell reloaded ammo) in 38 that are so weak they shoot 5 or 6 inches low at just a few yards, I found them annoying due to that but they certainly are a good starter load for a weak shooter. I say 357 because of the common ammo. The other calibers are great choices BUT they are harder to find. My second choice there would be the 32 or, if the 32 magnum can shoot regular 32s (I do not know this one!) then get the mag and shoot the regular. She can always work up to a stouter load but if you get a gun that cannot shoot the bigger stuff, she never can... so picking something that can fire both a hefty and a weak cartridge in the same gun is best IMHO. Smaller, lighter guns make the kick worse, as we discussed, so starting with a smaller caliber like the 32 or making sure you can find the extermely downloaded 38s would be good starting places. If you cannot find the weak ammo and cannot make it, just skip the 38 and start with a 32.

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