'Breaking Wrist Upwards' How to resove this?

[GLOOB]

Watch a high speed video, on an auto loader the bullet clearly leaves the barrel before the slide starts to retract, and it's slower to cause barrel rise in a revolver because it has to push the wieght of the entire gun. Light bullets and heavy bullets do not shoot low and high at normal shooting distances--they flat don't. I've checked it.

Actually, a revolver suffers a larger change in POI compared to a semiauto, in my experience.

The first part of recoil in a semiauto is the barrel/slide. The mass of the slide/barrel is more or less in line with the bullet. The bullet has left the bore before the major impulse of muzzle rise kicks in (the muzzle rise portion of the recoil stacks as the recoil spring is compressed, and not much has compressed by the time the bullet is long gone, as you've noticed.) A revolver is fixed. Since the whole revolver has to move with the recoil, it starts to rotate around the center of gravity, which is well below the axis of the bore, as soon as the bullet starts down the barrel.

That's one of my theories, anyway.

My other theory is that revolvers don't need a certain amount of recoil to function, so people tend to shoot a wider variety of weights/speeds to account for the greater variation in POI. I don't have a semiauto equivalent to compare to how my revolvers shoot with 125 gr magnums vs. 148 gr wadcutters.

Yet another factor is barrel length. A 3" revolver has about as much barrel as a 4.5" semiauto. The longer the barrel, the longer the dwell time.

 

[sugarmaker]

Thanks to HK Dan and Gloob's explanation, I learned my something for today. I always thought it was the higher hand position that made the automatics less sensitive than my revolvers. It's more like the recoil spring and slide inertia delaying the recoil impulse (and the higher hand position...). So by this theory, most semi autos WOULD shoot higher if the slide were locked. I'm mostly a big bore revolver guy, mostly because I hate seeing my cases flung over the countryside, so that's my main frame of reference. Good to hear other perspectives sometimes.

 

[Hk Dan]

Here:

http://www.youtube.com/watch?v=otpFNL3yem4

http://www.youtube.com/user/ultrasl...95&kw=bullet leaving barrel#p/u/0/4b07otXKERA

http://www.youtube.com/watch?v=iLml0TgmAUs

http://www.youtube.com/watch?v=BW93WQ98s-I

http://www.youtube.com/watch?NR=1&v=Um9Eos9bJDk

Case closed. If the bullet were still in the barrel as it started to rise, and I wanted my .44 to be sighted in at 100 yards (which it is) I'd need a front sight a foot tall to hit the target. If it were true that the sights account for barrel rise I'd need a new set of sights every time I changed loads and every time I changed the distance to the target. I don't. It's patently untrue on the face of the argument, and these videos prove it.

Part Two--there is no appreciable change in point of impact in my GLOCK 35 with a 180 grain and a 155 grain bullet at 25 yards. None. Zip, zero, nada. That is because the bullet is out of the barrel before the barrel starts to rise in recoil and there just isn't enough time for the lighter bullet to slow down before it hits the target. At 100 yards, there is. The heavy bullet retains it's speed better, and so long as it leaves the muzzle faster than the light bullet strikes the target at 100 yards, the heavy bullet will hit a bit higher. It's going faster, it has momentum on it's side.

For you equal and opposite types: We are applying equal and opposite pressure to both sides, but we're applying that force to an object of 180 grains versus 14000 grains. Of course the heavy one moves more slowly, requiring the full force of the charge for a longer time to start moving. The bullet does not require the full force of the charge to start moving. Good God, the PRIMER will move the bullet into the barrel. The charge does NOT give it's full force immediately, but builds relatively slowly in the explosives world. As the powder combusts it adds expanding gasses to the shot, but it doesn't all combust immediately when the primer goes off. The bullet on the other hand is moving almost immediately as the charge develops and is typically out of the barrel just before the full force of the charge is realized. The slide or the revolver is not. It's more massive and requires more time and energy to start moving. The bullet is accelerating the entire time that it's in the (stationary) barrel but the slide or revolver sits there like a lump until enough force is developed to make it move.

FYI: When you see a jet of fire leaving the barrel in a high speed video? The bullet is in front of that.

Of all the pablum that I've seen on THR, the sights accounting for barrel rise is the most laughable. Good God, that would mean that front rifle sights would have to be 24" tall. To shoot 1000 yards scopes would have to be tilted up 30 degrees.The barrel is longer, it does lift in recoil, and if it's true for handguns in your little flat world then it must be true for rifles, right? It's not. The bullet is out of a rifle barrel before it starts to rise in recoil too.

Dan

 

[BCRider]

Dan, while I'd say it's true that semis are not as badly affected by such things there IS still some effect. I ran into this with a 9mm pistol while trying out various loads for IPSC shooting. I went to 147gn bullets and found that they printed high on the target by about 2 inches over my POA at around 12 yards. Yet with 125's they hit spot on to my POA. On the other hand I always find that 115gn factory loads seem to hit slightly low. Not by much but just the group seems to center a touch under the center of the bull. Maybe a half inch? That makes it hard to tell for sure but it seems to be a trend. There was no doubt about the 147's though. They ALL went high.

The effect of varying the load on revolvers is also very noticable. And more noticable than semis for sure. As for your rifle comparison a rifle weighs a LOT more than a handgun and it's a LOT longer so the moment of inertia is a LOT higher for a rifle. Plus our hands and arms hold the rifle in a way that the mass of our arms are added to this. So you can't compare the muzzle rise of a handgun to a rifle and say that it would need a front sight that's many inches high.

You want to see a rifle print a hit at a point way above the sights? Just hold onto the foregrip with no pressure so it lifts out of your hand when it fires. At 100 yards the bullet will soar over top of the paper by some number of feet. All due to recoil lifting the barrel before the bullet has left.

But you've clearly got your mind made up on the matter and I can see there's no room for anything else.

 

[brickeyee]

It couldn't be more clear, the bullet is 20-30 feet downrange before the slide starts to move.

Wrong.

Period.

The slide has started to move backwards before the bullet has left or it would not have any momentum to continue rearward to cycle the action.

On a 1911 it has moved about 0.1 inch back back by the time the bullet exits.

Even in the links you posted you can step through the frames and see the gun moving before the bullet has exited.

THAT is recoil.

It may not be the final large movements, but it is moving and recoiling before the bullet has exited.

Momentum is conserved.

As the bullet moves one way, the gun moves the other.

 

[tuj]

 

[Hk Dan]

Brick and BC--I'll spot ya that you may see some slight movement on some guns, especially those with smooth actions and weak recoil springs, but you can't deny what you see. I mean, who ya gonna believe? Me or your lyin' eyes? LOL. My point is that there is no barrel rise before the bullet leaves the barrel. Look at the second video--a close up of the barrel bushing on a 1911. The bullet is GONE and the slide has not budged, but starts to as the video ends. The bullet is long down range.

BC, I too have tried different loads for USPSA and IDPA, including the 147 in 9mm. My conclusion? No change in point of impact at up to 25 yards, and I didn't like the recoil impulse of the 147. Too slow, it almost felt sloppy. Of course I'm used to shooting a .40 in USPSA Limited, where I have tried 155, 165, 180, and 200 grain loads in that gun. No appreciable change in point of impact at 25 yards and I settled on the 165. I like the snappiness of the recoil.

Oh--BC. Rifles. You have good points, but remember that you're dealing with VASTLY higher chamber pressures and speeds. I in fact DO shoot my .300 Winmag with a loose grip, barely touching my shoulder (the felt recoil is greatly diminished if it has to move the gun before it moves my collar bone). I routinely shoot 1000 yards with it, and the gun is zeroed at 400. It is point blank up until that point with that load, which could not be the case if the bullet were in the barrel as it started to rise.

The other obvious point here? You could never shoot consistant groups if the barrel rise was part of the equation. With a handgun if you grip too lightly with the strong hand, the gun raises up and right, yet I don't see the holes printing to the right at all. Why? The bullet is out of the barrel before it starts to rise. If you grip too lightly with the left hand, it raises up and left, yet you don't see bullets printing to the left.

You guys who buy into this one? Newsflash; the world is round. It's been circumnavigated several times and nobody found an edge. Leeches have little or no medicinal value except in certain cases--they are not a catch all cure as you may believe. Witches did not plague Salem; they were innocent. If pregnant women swim they will not drown the baby. The moon is not, in fact, made of green cheese, the earth revolves around the sun, and even though man was not made to fly and God has not given us wings, we can still fly aboard something called an "airplane" (Google it). For those of you still flat earthing it, I have some swamp land in New Mexico for sale--cheap! And a bridge in Brooklyn you should look at. Sound investment.

Tschuss!
Dan

 

[GLOOB]

HK Dan, I wonder if you've ever shot a 4+ inch revolver with wadcutters and 125 gr magnum loads in the same session. The difference in vertical POI is undeniable, and it's a shared observation by anyone who's done it that the heavier and slower wadcutters hit noticeably higher.

The mass of the bullet is tiny compared to the gun, but it only takes a tiny bit of movement to noticeably change POI at range. If you're a decent shot, anyway. If your groups at 25 feet are more than a couple inches big, you would never notice. Hmm. This brings up reason #4 why this effect is more noticeable in revolvers. Most people shoot a full frame revolver in SA better than they can shoot a semiauto (other than a nice 1911, mebbe!)

My point is that there is no barrel rise before the bullet leaves the barrel. Look at the second video--a close up of the barrel bushing on a 1911. The bullet is GONE and the slide has not budged, but starts to as the video ends. The bullet is long down range.

If you took a video of a guy holding a 1911 and was shaking like a leaf, then you played a hundredth of a second of it in super slow slowmo, you'd also see no barrel movement. But the guy isn't going to hit the bullseye.

*Actually, in the last vid you posted, you can clearly see muzzle rise before the bullet leaves. I wonder if you watched it closely. http://www.youtube.com/watch?NR=1&v=Um9Eos9bJDk It's not enough movement to require "a foot tall front sight to hit at 100 yards," which is good. Because that's not true. But enough to require a sight adjustment.

 

[SilentScream]

Just as a side note, don't back way out to 25 yards, that's excessive, go back to say 10 yards, you're still close enough to keep your groups respectable and get enough distance to evaluate your loads.

 

[Hk Dan]

The difference between what and what Gloob? I hate revolvers--the only one I shoot is my S&W 629, and then only when there is something furry and brown and dead at the end of the story. But check video 1 in my earlier post. The bullet--even your 125 grain semi wadcutter--is long out of the barrel before the barrel starts to rise. I can't explain your difference in point of impact without knowing what you're comparing it to, but it's not because the bullet is still in the barrel.

On a whim I called the head of Tech Support at GLOCK and HK a bit ago. After recovering from the laughter they said pretty much identical things. Yes, you may see .05" of slide movement as the bullet leaves the barrel, but no, you don't see the barrel rising. You simply couldnt shoot a consistant group with movement in the shot like that. (duh).

As I explained earlier, a slight change in grip strength effects how the barrel rises. With that being true, why don't the bullets reflect the "up and left" or "up and right" of that movement? Answer? Because they are long gone by the time it happens.

So, you have objective data--the explosion from a shot doesn't happen all at once. It builds slowly and the bullet travels down the tube from the moment the primer goes off until just before you have max expansion. There is not enough power to move the slide until you get pretty far down that power curve. That expansion happens at a very slow pace, compared to the world of high explosives. Light some gun powder with a match. It does not go <poof> and you will have time to move your hand before the fire gets too hot (if you're fast). Somewhere near the end of that "flash" is where the slide starts to move or the revolver starts to buck up (remember that it has to move the whole gun with a revolver, not just the slide. It's even slower with revolvers).

I've given subjective arguments--up and right, up and left, no change. Changes in bullet weight and target distance in my own shooting. I can shoot one hole at 15 yards. How the Hell do you do that with a moving gun? My .300 Winmag, with nearly 3 times the chamber pressure of a .45 ACP and yes, PLENTY of muzzle rise, is sighted in at a point blank range of 400 yards. That means, for the uninitiated, that I have the same point of aim from zero to 400 yards. How is that possible with the bullet still in the rising barrel? It ain't.

Finally, I've shown ya videos clearly demonstrating that the bullets are flying down range by the time the barrel rises. Good Lord, if all that ain't enough, pardon me but you are a glistening jewel in the tiara of ignorance. Or so stubborn that the flat earth crew would look open minded next to you. The bullet is not in the barrel when it starts to rise--it's just not. If you need more than what I've given you, you may be beyond help.

LOLOLOL
Dan

 

[GLOOB]

even your 125 grain semi wadcutter

I said wadcutter, not semi wadcutter. And there's no such beast as a 125 gr wadcutter. Before you make a lot more posts you later regret, I suggest you take your one revolver to the range with some 125 gr magnum loads and some 148 grain wadcutters and see for yourself. If you're a halfway decent shot with said revolver, you WILL see the difference, and you'll know what the rest of us are discussing.

On a whim I called the head of Tech Support at GLOCK and HK a bit ago. After recovering from the laughter they said pretty much identical things. Yes, you may see .05" of slide movement as the bullet leaves the barrel, but no, you don't see the barrel rising. You simply couldnt shoot a consistant group with movement in the shot like that. (duh).

He meant that the barrel is not tilting, as in unlocking, at that point, I'm sure. I'm just astounded that you'd call Glock on a whim to settle an internet dispute. And I'm not surprised they laughed at you. BTW, you could shoot a consistent group like that, if the movement is consistent. And it is. Because Newton's law is consistent.

As I explained earlier, a slight change in grip strength effects how the barrel rises. With that being true, why don't the bullets reflect the "up and left" or "up and right" of that movement? Answer? Because they are long gone by the time it happens.

They DO. If you change your grip for every shot, your group won't be as tight. I don't care how perfect your sights are lined up when the shot breaks.

Finally, I've shown ya videos clearly demonstrating that the bullets are flying down range by the time the barrel rises

Watch your own vids carefully. Esp the last one (which appears to be a long barreled SA, probably shooting slow cowboy loads in really slo mo, making it the perfect example). And tell me what your lyin' eyes see.

http://www.youtube.com/watch?NR=1&v=Um9Eos9bJDk

We're not talking a lot of movement. Just enough to need some sight adjustment.

Finally, ask yourself. If the muzzle doesn't rise at all until the bullet is 30 feet downrange, what the heck makes is decide to start rising at that point? Why doesn't it just stay perfectly level?

 

[wanderinwalker]

I like that video, very nice super slow-motion at the end you can see the movement starting before the bullet leaves.

Tell you what, I'll go ahead and shoot some 240gr SWCs @950 fps and some 240gr JHPs at 1300 fps out of my 6" 629 this weekend at 25-yards and post pictures. As good an excuse as any to go to the range!

BTW, I want to see a load you can shoot to "point blank" to 400 yards, even with a .300 Winchester Magnum. You do not have the same POA/POI all the way out that far. I'm going to guess somewhere between 200 and 250 yards you're at least 6-10" above your intended target (and I'm being generous). It's possible you might not notice much departure at 100 yards versus 400 yards, but...

 

[Hk Dan]

Point b;anl for deer hunting is defined as an 8" circle bud. It's point blank, zero to 400 yards.

 

[wanderinwalker]

Apologies for the 8" +/- trajectory, I forget how fast a .300 can throw bullets until I went and looked it up. I see a 150 will stay inside an 8" circle to 400.

Secondly, I thought I recalled reading about handguns and recoil and bullet impact, and it has been done before! And I remembered my 4" .357 doesn't exhibit the slower-loads print higher tendency.

Example: Toss a 158gr LSWC at 800-fps and it shoots to the front sight at 25-yards. Toss in some 158gr Magnum loads at 1200-fps and it prints HIGHER at 25-yards. Difference? Recoil. The Magnum load at 50% greater speed generates about double the recoil, and the barrel has moved further before the bullet exits. The difference is in the recoil generated!

My Glock 17 doesn't seem to exhibit as much variation, from 115gr-124gr loadings, but the autopistol rounds operate in a much narrower power window than the revolver. 115gr loads shoot low to right on, while 124gr reloads shoot right on to a bit high. It would be difficult for me to find something in 9mm that could give me the same 50% speed difference you can get with the revolver.

One other thing: Grab a pair of S&W K-frames, a .22LR and the identical revolver in .38 Special. The front sight on the .38 is quite a bit taller than the one on the .22LR to compensate for the recoil difference. (It's less pronounced on my M-18 .22LR to my M-19 .357, but noticeable.)

 

[JohnKSa]

You simply couldnt shoot a consistant group with movement in the shot like that.

Sure you can. Spring piston airguns are noted for recoiling PRIOR to the pellet beginning to move and yet excellent accuracy is attainable with a consistent grip/hold.

Recoil from a spring-piston airgun is primarily due to the motion of the spring & piston and therefore begins before the pellet moves.

Of all the pablum that I've seen on THR, the sights accounting for barrel rise is the most laughable. Good God, that would mean that front rifle sights would have to be 24" tall.

Not at all, the motion is very small. Just as a very small adjustment of a pistol sight can make a relatively large difference on a target downrange, a very small movement of the muzzle can make a relatively large difference on a target downrange.

No one is saying that the muzzle moves a LOT or that the slide moves a LOT before the bullet exits the muzzle, in fact, if you look at the video/photographic evidence I provided, it's clear that the amount of motion is quite small. It's also clear that there IS motion prior to the bullet leaving the barrel.

The reason it's not always visible in slow-motion video is that it takes a very high time resolution to observe it because things are happening very fast. In addition, the amount of the motion is not large which means the video needs to be fairly high-resolution and taken from fairly close to show the motion.

We are applying equal and opposite pressure to both sides, but we're applying that force to an object of 180 grains versus 14000 grains. Of course the heavy one moves more slowly, requiring the full force of the charge for a longer time to start moving.

That's not how it works. If equal forces are applied to two movable objects simultaneously they both begin moving simultaneously. The heavier one moves more slowly but they both begin moving the instant the force is applied.

That is because the bullet is out of the barrel before the barrel starts to rise in recoil.

What do you believe causes recoil?

If recoil doesn't start until the bullet is 20 feet downrange, then it can't be caused by the motion of the bullet because the bullet can't somehow magically reach back 20 feet to the gun and start it recoiling after it's already 20 feet away.

The gun must begin moving in recoil the instant that the bullet begins moving. Not only is that basic physics, there's simply no other logical way for recoil to be generated.

What do you think accounts for the clear misalignment between the sight line and the bore line in the revolver pictures I posted? The sights, when aligned, clearly aim the bore downwards--it's not even difficult to see the misalignment.

I've shown ya videos clearly demonstrating that the bullets are flying down range by the time the barrel rises.

No, you've shown videos that aren't detailed enough and/or don't have the time resolution to show the small amount of muzzle rise that occurs before the bullet leaves the barrel. (Actually that's not entirely true, one of your videos does clearly show muzzle rise before the bullet exits. The one with the single action revolver being fired shows definite muzzle rise in the third, slowest, segment of the video. Pause the video right as the hammer falls and place a post-it note on the screen so that it's aligned with the bottom of the barrel. Now let the video run forward until just before the bright flash occurs at the muzzle. The flash happens as the base of the bullet exits the muzzle, so the video is now paused with at least the base of the bullet still in the muzzle. You will see a small, but obvious, amount of muzzle rise.)

I have also posted other videos that have the detail and time resolution to clearly demonstrate that the muzzle rises/gun begins recoiling while the bullet is still in the barrel. I even cut out individual frames from one of the videos to make it impossibly easy to detect the movement without even having to watch the video.

How do you explain movement that clearly takes place before the bullet leaves the barrel in the video segment showing the 1911 muzzle & slide in the video link I provided?

 

[BCRider]

Dan, I often play a little game of "Revolver Roulette with five .38Spl and one Magnum round. I give the cylinder a spin and then stop and close it while looking away then shoot. My .38's will all be in about a 1.5 to 2'ish in group with the magnum round consistently about 2.5 to 3 inches lower than the center of the rest of the group. This being shot at about 12'ish yards.

This can only happen as consistently as it does if the gun begins to rise as soon as the bullet begins to move so that the magnum comes out sooner and hits lower.

As Gloob says it's an experience shared by anyone that shoots a combo of low and high velocity rounds from the same cylinder.

 

[Hk Dan]

BC--I had occassion to replace the recoil spring on my USPSA Limited gun. I went from a 15 pounder to an 11 pounder to increase the slide speed and get a bit better shot recovery. It worked. And the gun shoots just as it did before the change. It hits what I aim at.

Same gun--I changed out the flimsy factory sights for a set of Warren Sevigny competition back sights and a Dawson front sight. I put a micrometer on the back sight and ordered a front sight exactly the same height. The gun shoots as it did before; I hit what I aim at.

Now, i honestly don't feel competent to talk about revolvers or air guns. I did put two yardsticks on my 629, one across the top of the sights and one along the centerline of the barrel. They were even through 3'. I checked the top and bottom of the barrel shroud just to be sure--same result.

Now, this will be my last post in this thread. It has consumed far more of my time than I like, and on a ridiculous supposition by folks who won't be convinced otherwise. Therefore, I shall yield the floor, and remind you all that I have some prime swamp land in New Mexico for sale. Also a bridge in Manhattan, formerly called "Brooklyn" but now known as the HK Dan Expressway. I'll make you a real deal on either or both, but it must be cash.

Finally, I shall be contacting DuraGlit this morning to see if I can negotiate a group purchase on tiara polish for you guys--my way of saying "thanks". Let's keep those jewels glittering! LOLOLOL

Dan

 

[brickeyee]

My point is that there is no barrel rise before the bullet leaves the barrel.

You better get your eyes checked, and then take a physics course.

Looking at the relationship between a 1911 barrel, slide, and bushing will not tell you anything.

The action is still locked for the first 0.1 inch or so of recoil, so of course there is no relative motion.

If you look at the slide to the frame, the movement is very clear.

 

[Josh45]

I forgot I had made this thread...

Anyways, The reason for 7 feet is for testing purposes...I ran out of ammo at the time. Was suppose to be 7 ft, 14 ft, 21 ft.

I was thinking of carrying my revolver hence the reason for such close distances. I wanted to get practice in with the .357 mag loads. This thread has a lot of good information in it now and I need to review every post.

Thank you everyone for contributing to this and I will apply it at the range as soon as I get my bullets for reloading in.

 

[Blackstone]

I always thought that due to the consistent motion (Newton's third law), sights are adjusted and set so that any muzzle rise that impacts on POI are accounted for?

 

[JohnKSa]

I did put two yardsticks on my 629, one across the top of the sights and one along the centerline of the barrel. They were even through 3'. I checked the top and bottom of the barrel shroud just to be sure--same result.

You earlier stated that your 629 was zeroed for 100 yards, instead of a typical pistol range. That would mean that your sights would have to angle the barrel higher then would be typical for a lower velocity revolver sighted for 25 yards or closer. So it wouldn't be terribly surprising to find that your revolver sights and boreline are essentially parallel.

HOWEVER, if you think about it for a minute, the fact that they do align is actually proof that the muzzle rises before the bullet exits. Clearly if the bullet hits where the sights are aimed at 100 yards, the bullet has to describe an arc which would take it ABOVE the line of sight at midrange.

If the line of sight and bore line are aligned, as your measurement shows, then how does the bullet ever get above the line of sight?

 

[9mmepiphany]

sights are adjusted and set so that any muzzle rise that impacts on POI are accounted for?

They are...that is why I don't understand how they make laser bullets (for dryfire) work. When sights are correctly aligned, the bore is depressed

 

[JohnKSa]

People I've talked to who use the laser training systems that put a laser in the bore have said that you typically have to adjust the sights to get the laser and sights aimed at the same point.

 

[Hk Dan]

Says it all

 

[JohnKSa]

Perhaps I'm overly optimistic, but I'm not convinced you're beyond salvage.

Let's make it very simple. ONE question based on only either information you've presented/verified/measured yourself or information that is beyond any shadow of doubt true.

You claim that bullets from your 629 hit the mark (point of aim) at 100 yards.

We all understand that bullets must be aimed slightly upward in order to hit targets at long range. The trajectory charts I've found indicate that a .44mag bullet out of a pistol barrel zeroed for 100 yards is somewhere around 2-6 inches above the sight line at midrange. So there's no question that the bullets from your .44 mag pistol must rise above the line of sight (which is above the bore line) if you're making point of aim hits at 100 yards.

You claim that the bore line and sight line of your 629 are parallel.

If the bore and sights are aligned, what causes the bullet to rise?