I was discussing this phenomenon elsewhere with a fellow sxs shooter. The only reference I could find to it was in McIntosh's "Shotguns and Shooting" (p. 104). Nothing I could find in Brister, Zutz, nor in 3 books by Gough Thomas. MM says it causes a sxs to shoot somewhat low. Comments from the group on how big an issue it is for sxs shooters??

Are you thinking that possibly that sxs have more muzzle jump than o/u's?

Very little from W.W. Greener here regarding 'jump' and 'flip'

http://books.google.com/books?id=3HMCAAA...lip&f=false

I think I remember Churchill(?) claiming, as a means of promoting his 25" guns, that the shorter barrels had a tendency to flip upwards, compared to what he claimed was the normal tendency of 30" barrels to flip the other direction and shoot low. His, therefore, were better suited to incoming driven birds.

I believe that all barrels, even singles, exhibit muzzle "flip"

Muzzle "flip" is more of a problem for those of us who shoot SxS rifles and has to be really taken into account there. The right and left barrels do not flip the same.

A lot has been written about flip and you can find it on double-rifle sites. SxS shotguns have the same phenomenon but it is more easily demonstrated when you have a single bullet coming out of a barrel as opposed to a shot pattern.

Burrard talked about muzzle flip. Basically his consensus was the gun could be stocked to accomadate the flp for whatever length bll was desired. It would however be a mistake to have a 2nd set of bbls fitted of a different length as the fit could not accomadate both lengths. Been awhile since I read on this but as I recall he said the longer bbl would have greater down flip, don't recall any having up flip.

It would be interesting to see highspeed photographs of a SxS and O/U firing.

McIntosh was a wonderful poet.

I've had time to look it up and here's a link to a very brief explanation of barrel flip in a double rifle:

http://forums.accuratereloading.com/eve/...6481#2781096481

Same thing for a shotgun. That's why rifle barrels need to be regulated for a specific weight bullet/powder. Bespoke shotguns used to be (I'm not sure if they still are) regulated for the new owner's favorite load.

Might be interesting to ask fitters who use adjustable try stocks what they find when setting up SxS guns. A stock head for each make of gun might not be available, so info might be limited to guns that can be attached to the try stock.

I recall an article by Chris Batha about small gauge SxS guns needing high combs to deal with barrel flip. I cannot recall why barrel flip is exaggerated in small gauge (28-gauge, for example). The barrels are thin and light, but recoil is low, seems the effects might offset, but apparently not in his experience.

I have most of MM's books, a really a big fan of his writing. But one time I found he missed the mark, when writing of muzzle flip with SxSs in the context of gun fitting. He advised that stock modifications for a properly fit SxS should allow for muzzle flip by putting the point of impact above the point of aim. Left me scratching my head, wondering why muzzle flip would take a vacation when shooting at the pattern plate, but come back home to lower the pattern to point of aim when shooting birds or targets.

Jay

Ditto.

that reads like more of the gunners' intuitive physics that we are all so familiar with than a reality. I would suspect that the off-axis bbls have as much to do with flip as the direction of the rifling. Are double rifle bbls rifled in opposing directions? Why not? Muzzle flip is derived from the geometry of the wood/meat interface and those silly energy/recoil equations. I can make just about anything flip like a MFer. And conversely reduce it to a minimum allowable by other dimensions. It's a system and rifle people are notoriously iggorint of proper gun fitting. Shotgun people marginally less so. Maybe.

I missed the ref to altering bbl harmonics by changing loads. Might be a clue to those pesky regulation issues in the rifles.

I could be wrong but I try to have Newton (y'know that energy, mass, force vectors kinda stuff) on my side so.......

have a day

Dr.WtS

i believe muzzle flip is also a funtion of pitch of the stock. I had an SKB 20 ga that kicked up like a mule. A gunsmith looked at it and said the moron who installed the pad had the opposite pitch required to fit me. He changed it and re-installed a pad and it really changed the "excessive flip"

Jerry

Not an issue for me, Larry, in competition or in the field. The only time it is an issue for me is if I try to compete with a straight gripped gun. I have said before that I do not have as secure control of the gun going into the second shot with a straight gripped gun as with a pistol gripped one. Many have commented otherwise, so it may be just me. But, the heavier the load the more it is magnified, so I think many here who use light loads just may not notice it.

I have never noticed any downward flip with a S x S. I am sure there is a bit of lateral flip, because the barrels are positioned in that manner( side by side). Stands to reason, because there is upwards flip with an O/U, more pronounced with the top barrel as it is farther away from the "center line". But, sideways movement is never noticeable to me. It is there, tho', and regulation takes this into account. If it weren't there, convergence at the muzzles would not be necessary to counteract it.

SRH

Interesting perspectives. I think some of the discussion is confusing flip, which happens before the projectile(s) leave the barrel (otherwise it would not impact where you hit) with recoil. Recoil is always going to cause some upward movement of the gun, but if that had an impact on point of aim, then all guns would shoot high.

Not sure how important it is in the grand scheme of things. Re Churchill and his XXV guns, part of the discussion that caused me to post the question was the contention that shorter barrels don't flip as much as longer ones. Which seems to run against the belief that longer barrels are an asset in target guns.

Who, before you, described flip as that gun movement which occurs before the projectile(s) leave the barrel? Maybe you are assuming what others are confusing?

Isn't what's important the end result of all the forces at work? What does it matter what occurs before the projectile leaves the barrel or what happens the instant after?

Not trying to be argumentative, but rather to understand the point of the question. The question was, how big an issue it is for S x S shooters. What the end result of all the forces at work is, is what causes any effect on a shooter. Right?

SRH

The issue of muzzle flip as introduced by Larry pertains only to where the shot charge hits, not to any interaction between the gun and the shooter. Muzzle flip as described by MM is a downward flexing of the barrels that causes the gun to shoot lower than it would if the barrels were rigid.

Jay

In a SxS the right barrel will flip up and to the right; the left will flip up and to the left. When barrels are regulated they are adjusted to negate this flip. However, they can only be regulated for one mass of projectile and one velocity. This is a little difficult to see in a shotgun but is very obvious in a DR.

An O/U will flip upward.

However hard I've tried to detect flip in my shotguns using normal loads, I never could be convinced I culd see it.

However, in a DR it is very obvious.

That's exactly what I meant when I said, "Isn't what's important the end result of all the forces at work?". The interaction between the gun and shooter absolutely influences where the shot charge hits. Much happens before the shot charge clears the barrel. All of it influences the impact.

SRH

True Stan, all affect point of impact, but "muzzle flip" is a narrower term, pertaining only to the downward flexing of the barrels, which I don't believe is affected by the shooter -- except that the shooter happens to drop the hammer.

jay

I understand muzzle flip in SxSs as discussed and defined by MM to mean only downward flex of the barrels, not movement of the barrels as a whole from the axis/plane they're in at the moment of discharge.

Brister discussed muzzle flip (using the term "downflip" at one point) and recoil characteristics of the over-under vs. side-by-side in "The Art and the Science," pages 43-46 (1976 edition).

The only "Flip" which will affect where the shot hits is that which occurs before the shot leaves the bbl. You can turn the thang around after the shot leaves the bbl but it won't hit behind you.
The "Flip" which Burrard discussed was not the rise from recoil. It rather was a downard flexing of the muzzles which occured as a result of the inertia of the muzles trying to stay stationary as the gun rose in recoil. This would offset to some extent the recoil rise causing the gun to hit lower than it otherwise would. This flip, flexing or bending of the bbl (Call it what you will) is a different thing than recoil rise.
Recoil rise is quite prevelent in short bbl guns such as handguns. Bore sight a pistol which is properly sighted in & you will invaribly find the bore axis is point "Below" where the shot is going to hit.
The longer & less rigid a bbl the more it will be affected by Flip. I do believe this is what Larry was seaking of, not recoil movement. That part of the recoil movement which occurs prior to the shot leaving the bbl is of course why the bbls of a double converge.

Thomas Garwood also mentions that long barrelled sxs tend to hit lower (Shotguns & Cartridges, p.182), although it does not explain why. Charge weight is also mentioned by the same author (Second Book, p. 181-182) as a reason for low hits with heavy charges. Both fenomena could well be explained by flip.

EJSXS

Thanks, Jay. You got it. Recoil, as far as hitting goes, can have an impact on the shooter. (Example: Flinch in anticipation of recoil.) Flip impacts the gun independent of anything the shooter does or does not do.

In looking at a lot of high speed photographs, I cannot recall one where there was any apparent movement of the barrels before the projectile exited the gun, other than with a very few large caliber handguns. And they went up. I suspect the phenomena may be much more pronounced in guns with thin barrels, but I don't really even know if it exists.
I am sure someone could work out the mathematics of the whole thing. I'm an engineer but I just don't have the energy any more. Al long as the shot hits where I want it to I don't really worry too much about the esoterica. In fact I try NOT to worry about such.

I own a 27" SxS which clearly shoots 6" low for me, both barrels on a pattern plate. Not sure why. Can't hit anything with it. I do much better with high shooting guns, specifically O/U's. I have shot a lot of competition target shooting and I have read, and believe the more one shoots the higher shooting gun that shooter requires, ESP in the discipline of trap shooting. I guess this is one reason I shoot O/U better than SxS, but I truly believe most SxS's shoot lower than O/U, and whether this is due to muzzle flip, I'm not sure??

Right. BUT that skips over a lot. BUT what really happens is more like this. If you isolate and fix in space the action/bbl breech unit, that unit no longer has a mechanical "up" or "side" reference. If you want to remove the infinitesimal gravity component just point it straight up. When the thing is fired there is no motion in the action unit thing and as a consequence there is no "inertia" in the muzzles resisting rotation to produce some imagined intrinsic flip. What there is is a vibration of some unknown frequency and amplitude generated and the nodes will appear at unpredictable positions since the freq is not known. Pix of vibrating rifle bbls reveal this. Multi-bbl things by virtue of a really complex structure are not gonna vibrate like that and suggesting that there is a single vertical plane of vibration is just absurd. Muzzle displacement, likely in the microns dimensionally, is unpredictable and would vary with different loads altering the amplitude and freq of the vibrations. That's why rifles shoot diff POI w/ dif loads, the vibrational nodes occur at diff places. SO now we have a muzzled displacement that is unpredictable and likely so minuscule as to not exist. And that brings us back to the unfixing of the action in space and mounting a whole gun. NOW the action can rotate and that rotation is dictated a total extent by the geometry of the gun bore axis and that gun/meat interface I mentioned earlier. Now there is an "up" and "side" and force vectors working in each. And that controls the rise of the rise of the gun that 2-piper notes, even while the charge is still in the bbl. And with what he said if you sight in a pistol in a machine rest and then shoot it in hand the poi will radically change, even if you rest the meat on something.

SxS's do not shoot low, they shoot to all kinds of funny places due to the induced vibration in a really complex structure but to so small a distance that measuring it would not be likely. The poi of any gun is totally dependent on the position of whatever sighting apparatus is used and if that is the front bead and your eye then you just gotta get your eye in the right spot. And the magnitude and direction of those recoil vectors goes back to the geometry of the gun/ meat interface.

Tho I've never bothered to measure it, I'd bet vital body parts that all of my guns, O/U's and SxS alike, have no significant difference in the bore axis / eye-bead relationship since they all shot to +/- the same poi. And they all recoil pretty much the same since the stock dimensions are +/- the same as well.

HTH

have a day

Dr.WtS

Thanks for the Brister reference, Bluestem. I'd forgotten he addressed it. Looked in the index under "muzzle flip" and didn't find anything.

Well I don't have the means whereof to fire my shotguns while suspended in space, in fact I don't believe this can be accomplished within the confines of gravity. While true this info is of little practical value to me. As I do fire my guns from the shoulder then the ppoint of contact at the butt is below the bore axis, which does indeed cause the end of the bbls to rise upon firing as they are pivoting off that contact point. The flip we are speaking of comes about by the muzzle not rising quite as fast (In proportion to its length) as the breech, or it "Bends" a bit.

This could all be seen clearly if one could simply shoulder a gun, mark the bore axis point on a target & then without moving fire the gun. You could then compare the center of the pattern with the where the bore was actually pointing. Marking directly above this center point by the amount of drop of the charge over that range would show where the bore was pointing at the tim the shot left the muzzle. "IF" you could then without changing anything else liminate the "Flip" & fired another shot you would get a point of impact slight above the first firing.

Remember that "Flip" does not necessarily mean the gun is going to shoot Below where its bore was pointing, it just won't hit as high as if it didn't exist.

Do I recall Brister describing the flip by the flexation of a cane pole...that if you held the stout end and attempted to quickly flip the far end upward, the middle of the pole would first rise while the far end would arch downward before rising? It is easy to see in a pole, but does a barrel do it to a much lesser extent?

Brister might have said that somewhere, but he didn't use that analogy in the referenced passage from his book.

It is always so distressin' to have these enlightening discussions remind me of how much I must have missed by dozing in my physics classes at Hogwarts.

So I'll be off now to work on an anti-flip spell for my bamboo barreled guns so as to optimize my fire hose shooting technique.

have a day

Dr.Wts

Don't trouble yourself too much-any day now, you kalifornicators will be down to assault butter knives, and the fragrence of spent gunpowder will be but a fond and passing memory....

Best,
Ted

But what does it matter? I'm dense, I guess, but what does it really matter if the barrel screws itself into a corkscrew, and then straightens itself out after firing? Isn't what matters, where the shot charge hits?

All we do is manipulate the drop, pitch, etc., to get the shot charge to hit where we want it to. Regardless of what configuration the barrels are in.

SRH

I'd think if some deflection or vibration happens to the barrel, wouldn't it matter how the shooter dampens or may affect that vibration.

edit to add, aren't some flinches the inability to do the require muscle input rather some additional recoil altering muscle contraction, so things like release triggers were developed.

Craig: from flip to flinch

"Flinch", "yips" in golfers, and a host of other movement disorders are now classified as a 'Task Specific Dystonia'
http://www.wemove.org/dys/dys_flimb.html

The problem has ended the careers of some professional golfers and musicians. Aynsley Smith PhD, Director of Sports Pyschology and Sports Medicine Research at the Mayo Clinic, Rochester, and Dr. Charles Adler of the Mayo Clinic, Scottsdale have researched the problem extensively, and a 'cure' remains elusive.
Mine is so bad that I 'flinch' trying to click the mouse

A different issue is the anticipatory lunge forward in response to recoil. I briefly, in the mistaken notion that it would be fun, tried a .410 chamber adapter in a 20g and found myself shooting a foot under the skeet targets at station 2 from lunging forward against no recoil. No idea what the barrel was doing.

Stan, "the matter" is that a sxs, if stocked to the same dimensions as an OU, may shoot lower due to flip. You're correct: what you do is "manipulate" the dimensions to change the POI. Brister suggests that an advantage of a sxs shooting lower is that it can be stocked higher, which allows the shooter to see more rib. In my own case, I've recently determined that on rising birds--woodcock being an excellent example--I seem to shoot better with a sxs with less drop than some I've used previously. 2" DAH or close to it, rather than 2 1/2".