Does Gun Recoil Affect a Bullet's Accuracy and Velocity?

The recoil will be in line with the bullet's travel and shouldn't produce any deflect IF the support for the weapon is also in line with the recoil. Of course in a practical gun the barrel is above the grip so there will a tendency for the barrel to kick upwards, the inertial mass of the gun presumably delays this a bit. Those who actually shoot these things will have to say how much it effect the shot.
Regarding the glass, if it as a very acute angle it may deflect the shot, but I'd think it would need to be quite quite a grazing angle. I'd guess + / - 45 degrees wouldn't do much.

I havn't shot revolvers or pistols so this is just my uneducated opinion (so feel free to set me straight).

Out of interest, when shooting at a sand bag, barrel full of water or bullet proof glass an arrow can penetrate better than a bullet from some handguns.

Del

40 years since last fired a shot.

1. Don't think so unless you close your eyes in anticipation of the shock. I cant remember ever making provisions for recoil during aiming.

The bullet is out of the barrel very quickly mostly before the backward acceleration can cause enough movement to take up the slack..

If you don't have sufficient grip (like a banana sized hand on a Baby Browning) recoil inaccuracies may occur.

2 If shot at an angle at the plane of the glass pane it would be deflected.

Hendrik,

With your point (1). I have known a few (Thankfully not many) who flinch when they shoot and get strangely good results by adjusting thier scope to counter the Down&Right "tug" when they pull the trigger and flinch.

But a reasonable to good marksman should Not need to cater for recoil or anticipate recoil which I suppose is what I'm really getting at.

Regards,
Sapper

Sapper

True.

I never liked bad shots. If they are Lucky to hit the target they mostly only wounded the poor animal.

What I did with bad shots when I was in the position to do so was to load their rifle with blanks and then shoot almost simultaneously. When we arrived at the antelope I usually first teased him that I think he actually missed and that the animal died of shock because there never even was a wound visible. And then after close inspection find the hole and praise the man for being a good shot. (Very hypocritical)

You have asked two questions. One is does recoil affect the accuracy and velocity of a bullet? The other question is will glass defect a bullet? You are correct that recoil begins early, and this is why the floating barrel was determined as more accurate than the stock rigid barrel.

However this is not so much a function of backforce, as it is of forward force that distorts the rifle barrel, and causes a flex, or whip, most notable in high caliber rifles, like 270 hunting rifles, or 50.Caliber sniper rifles.

(The way I understand this, is that the bullet moves down the barrel followed by force and a vacumn that twists the barrel upwards, then snaps it downwards at the time of bullet exit.) Though it would seem to make sense that an immovable backstopped rifle would produce a higher velocity for the bullet, I doubt it really makes any difference in the velocity of the bullet, feeling out the gun, the velocity of the bullet will move at the same speed, no matter where the gun was.

If no recoil was allowed then even if there was velocity increase, it would be slight. Doubtless the speed, velocity of the bullet, would be very slight for small calibers, though it may be of interest to know for larger calibers.

As far as your second question: I would expect that after a shooter positions himself to fire at a target through glass, like the glass of a skyscraper, from over an angle of between 83 to 90 degrees, appreciable deflection would occur.

I'd not much worry about it from most any degree when we are talking about single pane glass like I live with in this house from the 40s.

"Ready, Aim, Fire!"

Steady?, (Steady, Aim Fire!)

P.S. these estimates are seat of the pants and only come from shooting rifles and shotguns in non military settings. I do not claim to be an expert, and expect some other to correct me at my guesses. I tried to find the book in my library that detailed barrel whip, but didn't.

Not much to add to any of these great comments, except nowadays most (military)sniper work is done with .50 cal rounds and these tend not to be easily deflected.

They do tend make something bleed at both ends.

the lighter the bullet, the higher the velocity and the more oblique the angle, the more likely a deflection.

Thats why I stuck with .30 cal.

We saw this video in our community police academy Its how "Not to;"

http://www.youtube.com/watch?v=NyP2vT0dwSY

When deadly force is authorized, its meant to be used; not trick shots.

This one is not for the squeamish, it is real footage, .50 cal long distance work from Afghanistan, DON"T WATCH IT OF YOU DON"T LIKE VIOLENCE: http://www.youtube.com/watch?v=TOZoYIoyjuM&feature=related

milo

So then, if you gave such a rifle to guys on the International Space Station, what use would it be to them? I believe that the machine would work in weightless environments, though I would be concerned with temperatures.

Obviously silencers, which inhibit accuracy, would not be called for.

If you can hit somebody from a mile away on Earth with a .50 caliber bullet, how far away could you hit a similar sized object in outerspace, or from the typical 178 mile up orbit of the ISS?

The shots shown in the video, and known as possible by handsight of men, or women are awesome.

As I have gotten older I become more and more fond of a shotgun.

For awhile I did carry with me a Smith and Wesson 22 longrifle semi automatic pistol, that was very accurate for 100 yards, which is close when you do it.

Should it at all be practical to shoot at spacejunk with regular old rifles, or other off the shelf weapons, the Dum Dum bullet may have applications.

In another Potato Cannon Thread, we have discussed recoilless rifles, and projectiles appropriate to the problem of defense of the International Space Station from Space junk.

If I had my way, I'd be able to ask the crew on the International Space Station what they would like to have around for experiments from the Crows nest.

Certainly forward shots at Space Junk by an astronaut, even if accomplished using cannons with recoil, or rockets, ought not be much setback considering the mass of the International Space Station.

Side shots of any appreciable recoil, could need to be counteracted, depending on where the thrust was levered.

Therefore something with an appropriate Dum Dum splat shell out of something like a Matador Recoilless, would be recommended for practice, if not for full out last Hail Mary defensive measures.

P.S. Prior post became off topic, and plus I became silly.

Accuracy, yes. Velocity, probably can't measure.

As far as recoil affecting point of impact of projectile, the gunner will have taken this all into account prior to putting the weapon in service. The sight picture will produce the desired results, if the shot is properly executed.

Solid projectiles are preferred.

No, recoil does not directly affect accuracy. Recoil occurs after the bullet has left the barrel. The barrel motion caused by recoil is happening long after the bullet is downrange.

The only way recoil affects accuracy is if the shooter flinches in anticipation of the recoil.

yes, in a gas operated weapon , the " recoil" is felt from the pressurized gases escaping the barrel, so , in a word: NO , the recoil is not a factor in taking aim, or any of the calculations to set up "my " shot.

As far , as questioning the validity of TV, well, entertainment is not bound to the physical laws of the universe ,

..in the ballistic example given : as to the statement that almost all sniping is done with the .50 cal:..imho: if i was tasked to make the shot from a range where the target was " shielded " by glass..choosing the correct caliber , ensuring that enough " knock down power " is delivered to the target...i would determine my best vantage point for the shot then select the caliber to do the task..the "distortion" { refracted image vs real position {from the glass would be a factor i'd think about as well, keep in mind as well, most snipers prefer to make their own " loads " ..i.e. how much powder is in the shell....as well as armour piercing rounds , depleted uranium, specialty rounds { sabots} ...and lastly .. maybe i fire a large burst instead of a single shot...

The recoil is from moving the bullet from 0 Ft/Second to maybe 3 or 4,000 Ft/second rather suddenly.

As a crude example, if the bullet and the rifle both weighed exactly the same as each other, they would both move suddenly apart in exactly opposite directions at the same speed!!

It is the large difference in weight between the two that allows the gun to remain fairly still and most of the energy is given then to the bullet!!! The small proportion that the gun absorbs is called "recoil"......

GA

I'd just add 'virtually all' to "Recoil occurs after the bullet has left the barrel"

And maybe explain; recoil is mostly due to the unbalancing of forces when bullet and 'jet' of gas exit the barrel.

Of note; is the muzzle configuration on the 50 cal is not an 'anti rise vent' approach.

It's the main reason such a round can be used in an 'in line of drive' stock design, without breaking the operator (after the bullet has left)

A bullet fired from any well constructed rifle will not be deflected by recoil, more than 1/2 to 1 MOA, which is most easily understood as a ratio of 1 inch of deflection per 100 yards travelled. "Felt" recoil, which is the human factor, comes into play after the round is fired and exits the muzzle, because the human shooter reacts to both the physical and audible evidence of the shot. But because of our relatively slow reaction times, unless we anticipate the event, we don't pull the shot significantly.

A badly constructed rifle, or a flimsy barrel, may in fact add far more recoil affect to the overall shot, since a round leaving the muzzle at 3000 fps, from a 24" barrel, has to accelerate at a rate of 1500 fps for each foot of travel. I haven't done the calculations, but have seen some that indicate that the acceleration experienced is somewhere in the area of 5000 Gees. Straight forward, it might not mean much, but even a slight mis-boring of the barrel, on the order of millionths of an inch, probably adds up to a lot at that rate.

In addition, since the bullet has to spin up at a similar rate, I've seen the same calculations for spin acceleration indicating a further 5000 Gees. That surely has to torque even a well constructed barrel somewhat. So it surprises me that with my old 30-30 Winchester lever action, I can consistently make sub MOA groups, as long as I allow for sufficient barrel cooling time between shots.

But recoil doesn't seem to play near as large a part, even at that short range, as does breath and body control.

Micah

In a correctly designed, weighted and used rifle, the recoil should not affect the trajectory of the bullet at all. The reason simply being that when "sighting in" a gun, this is fully accounted for in that process. Provided the shooter also did the "sighting in". Especially important for longer shots over say 400 meters.....

There are two possible scenarios in the real world when taking out a human target behind glass, that can be used. There are maybe more that I have not heard of, I am not a sniper by trade!!!

1) Two shooters, one shoots 1/2 second or less before the other, first shot breaks the glass (pulverizes it). Both shooters must be as close as possible to each other physically for best effect, one calls the timing for both.

2) The (single) shooter uses a Self loading type of rifle, be it Kalashnikov, Belgian FN or other make is mostly immaterial. (This goes against the grain for many Snipers as the ones I have met usually prefer bolt action rifles for consistency over long ranges.....)The shooter then shoots twice, as quickly as he can. This would work better over shorter ranges of 200 meters or less.....

Some really good snipers can operate a bolt action and stay on target as well, quickly enough to not need the SLR effect.....

Either method makes usually for 2 wounds, with major shock and probably instant death for the target. Good sniper(s) will get both bullets usually within a 6 inch circle, in the middle of the chest, sometimes even going for a head shot(s), if the chest is not visible, or the range is short enough.....head shots are harder to "fix" medically, but heart lung shots are also difficult!!! Ask any deer that was so shot!!

Modern armoured glass will usually fully stop one or more high powered rifle bullets no matter at what angle they are shot at.........I believe the white house is fully protected in this manner.....as are many other important buildings around the world....

Teflon coated bullets will be used if there is a possibility of armoured glass being encountered. Some early glass versions are penetrable with such bullets I am told.....also, the later bullets will be made of spent Uranium for certain western snipers.....Old USSR ones too I expect!!!

If nothing else can be done, then a short range missile with concrete penetration capabilities will be used.......makes a big mess though!!!

Ronseto, Andy, All,

This is a really informative book on this subject.

I didn't give the link last night as I forgot the title and it was in my shelf at work.

STALKERSSHOOTERS

Enjoy.

milo

Andy,

I would like to give you a GA for such an exhaustive posting. But before that, I would like you to tell to all of us where have you been on November 22, 1963 about noon, central time?

Firstly I was never a sniper, except maybe in my dreams. I liked shooting, was a reasonable pistol shot in the Navy....also quite good with an O/U....

As a sniper, even drinking coffee or tea would put you off the mark.

I also smoked at that time, not good for a sniper, both for heart rate and the strong smell......

Actually, I remember exactly where I was on that date/time, I was playing badminton at the local youth center in Waltham Abbey, Essex, England!!!

Sorry, not me buddy......it must have been a Tuesday or a Thursday I think....but not certain anymore!

Many accurate and excellent answers, had to choose GAs on who got in first.

And while the 50cal is increasing in popularity visibility in the military, probably the most common caliber for sniping is variants of 30cal 7.62. Logistics have more to do with this than preferences. But seriously the 50 is better at anti-vehicle than anti-personnel.

For preference I was VERY fond of the 264 Winchester Magnum, a load largely unavailable now. So availability even effects us civilians - with my new fave for long range the 300 Winchester Magnum, but with a compensated barrel.

First off a disclaimer. I was not a sniper when I was in but I did serve with one and did receive some training in the area.

A number of assumptions have to be made with regard to your first question.

1. The shooter is properly trained or the weapon is properly supported e.g. bench rest, sandbagged, etc

2. The weapon is of sufficient quality.

Assuming these two prerequisites are met then the recoil will not affect the accuracy. People have mentioned barrel harmonics having an effect, which is true they do to a point. Generally a sniper grade weapon will be tuned to the point where their effect is negligible. The shooter will have zeroed the weapon, which means that they know how it handles thus allowing them to counter act any residual effects.

Velocity on the other hand is a whole other ball game. The recoil will not affect it but humidity and altitude will. There is a device to measure velocity but the name escapes me at the minute. It looks like two triangles separated by about half a metre. Mounted on a stand. They are small triangles maybe 20cm a side.

Your second question also has a number of prerequisites attached.

What type of glass you are talking about. An ordinary single pane window such as you would find in a house will have no affect. A car windshield or plate glass found in a high rise would.

What type of weapon and ammunition are we talking about?

Lets say we stick with the sniper and his weapon. In the military context that will generally be a bolt action rifle of one of the following calibers 7.62mm Nato, .300 magnum, .338 Laupa or 12.7mm. The last is less common than the first three and is used more for anti material and extreme range work so we will discount it. For simplicities sake I'm going to go with 7.62mm Nato. The pretty much standard round used in a sniper rifle is a boat tail hollow point round. This round is designed to deform on striking its target in order to dump the maximum amount of its energy into it. So when shooting through glass it is generally recommended to use a barrier penetrating round. There are a number of specialist rounds available but in a pinch a good old armour piercing round will do the job. They won't deform and thus pass cleanly through.

So in conclusion the answer like so many others in our respective fields is it depends on the situation at hand.

Thank you all for your answers. Since this was a question, the answers I read all seem to agree so I am confident in their validity and more or less confirm my thoughts on the subject.

On the glass question, I think distance would be a major factor. Most rifles are, by nature and design, long-range weapons for rural use (hunting or battlefield). If the target is behind a window, then we are looking at an urban or suburban setting where the distances tend to be much shorter. The bullet would not have lost much velocity due to air drag, so it will maintain its trajectory better.

Then the next factor to consider is the glass. Thicker or bullet-proof glass would obviously stop or deflect the bullet. Double-glazing increases the chances of deflection. Modern glass breaks into small beads, while older glass tends to produce shards that can also produce wounds in anyone who is close enough to the window.

Hmmm, there seem to be some odd ideas about what recoil is...

Newton says that action and reaction are equal and opposite.... as the bullet is accelerated down the barrel, the barrel is also accelerated back towards the shooter.
The large mass of the rifle compared with that of the bullet means that this acceleration is much less than that of the bullet (Force being mass x acceleration).
Once the bullet leaves the barrel there is no more acceleration of the bullet, there will still be gas accelerating out of the barrel, although how significant this is compared to the accelerated bullet I don't know (I'd guess, not very, although the escaping gas, can be directed to help overcome recoil). Both bullet & rifle are still moving e.g. They both have velocity... this is available energy to move the weapon after the bullet has left the barrel...
So the reciol certainly starts as soon as the bullet starts to move.
The force directed back at the shooter and the velocity of the rifle back towards the shooter is the recoil. If the shooter is holding the weapon firmly then his mass (or that of his arm and shoulder) is added to that of the weapon reducing the acceleration....This is why a shotgun held just off the shoulder, rather than pulled into it can give you a whack.

Del (feel free to shoot at me ...)

.... as the bullet is accelerated down the barrel,

I didn't think I needed to correct that as someone would come along

why a shotgun held just off the shoulder,

This is also why shooting an M1 (11lbs firing 30-06 rounds) is less painful than many lighter weapons with lighter rounds. Carrying the M1 was a burden, but it was a sweet shooter with little recoil.

Good explanation.

"It doesn't go anywhere."

Looong ago I had a friend who collected rounds of ammunition.

What he did when he received a new one was to (in a crude manner) remove the bullet throw the cordite (or whatever) out and put the bullet back into the shell.

One day the round did go of resulting in a flesh wound at his pulse. and the bullet was gone.

His arm became more painful over time and the doctor found the bullet in his elbow after taking a xray. It must have traveled just under the skin towards his elbow.

If I could rewind about 50+ years.. We used the British .303 rifle.

It was a very accurate rifle. In fact for our "sharp shooters" badge (and
an extra 2/6 a week in pay) all we had to do was put 5 rounds into the
area of a penny at 50 yards. By luck I did, and since only 3 bullet edges
could be seen - they claimed I had put 2 "over the top!" (of the target!)

The rifle was (killingly) accurate at 1,000 yards! Using a lift up long range site.
(victim was almost out of sight) Unimpeded, the fired round could travel up to
3 miles! (with less effect naturally.)

More recently, for my son's wedding in the US, I (gleefully) experienced a pistol
shooting range (lucky devils over there!) and fired several makes of revolver.

My (the) accuracy was appalling! Barely hit a barn door. (Now I don't believe the
movies at all!) What did impress me was.. I could hire (yes HIRE!) an "uzzy" (for
any unknowing a pistol like machine gun) to spray hundreds of rounds a minute,
for only $25 dollars a day! i.e. Hire it today $25, shoot masses of people like crazy,
then take it back for your deposit! What a country! (but I loved the range.)

Not to clever on velocities or recoil - I only drive them!

jt.

It only hurts when I laugh.

ps.. Don't know why I have been "up graded" to a guest?
Perhaps you'll recognise me by my initials! (jt.)

jt.

Hatchers Notebook by Julian S Hatcher is perhaps the best reference work on ballistics ever written. You should be able to find it on Amazon

I found this and have read every post kind of a dis-believer of 'kick' affecting round placement.

Last weekend (10-16-2010) I shot a .30-06, Remington, Model 742, semi-auto.

180 Grain round @ 25 yrds equaled under 1" group 3" below dead center. Shot 10 rounds for sighting in. Left scope as was because curious of the 150 Grain.

Put in some left over 150 Grain rounds (4), aimed dead center and hit 4" below center all grouped under 1" circle.

Shooting on bench with support so zero gun movement. Any ideas why then the 150 Grain hit 'lower' then the 180 Grain?

Trying to figure this out and only this left is 'Recoil' affect. Shells are new, purchased 2 weeks prior.

My guess is the powder charge is lighter on the 150 gr.; presuming same sight picture for 180 as 150 (you didn't say for the 180at the same powder charge, the 150 should go faster, and since faster, hit higher at same range. by hitting lower, it is demonstrating that it is travelling slower.

unless you changed your hold and securing of the rifle when shooting, I wouldn't think the recoil was the issue between rounds.

Between shooters- perhaps. but not same shooter same support.

my 2 cents.

Milo

Thanks for the reply.

Rounds purchase off the shelf. I'll dig deeper into the shells and compare.

Headscan,

I had a look at some of my old reloading data and I have a probable explanation or two for you.

1. The 150 grain projectiles have less charge and therefore are already past the peak of the ballistic curve and dropping.

2. This is what I believe is more likely is that the 180 grainer is shooting flatter. ie less curve.

The only way to prove either way is to fire two shots to prove point of impact for the 180 grainer. place paper targets at 10, 20, 30, 40 & 50 yards and fire one of each of the rounds, checking the targets after each shot. you will then know the why?

You could get a reloading manual and work out the ballistics but it is time consuming and does not give you the "proof".

Regards,
Sapper

Thanks for checking. When things settle down for work I'm going to revisit this 180 vs 150 theory and check that it.