doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Short chambers and recoil?

You beat me to it, Ted.

As for only the gauge and not the chamber length . . . well, in the case of the specified 12ga, they make them from 2" up to 3 1/2". If you could fit a 3 1/2" shell in a 2" chamber, or even a 2 1/2" chamber, I think you'd get a rather unpleasant surprise when you pulled the trigger. That's too much additional case length . . . not to mention the fact that the 3 1/2" 12ga has a much higher proof than the 2 3/4" or 3" guns. And even higher still than the 2" or 2 1/2" guns.

Most loaders are set up for 2 3/4" hulls, which are readily available (and of very good quality) in this country. Given the price of factory 2 1/2" shells, it makes a whole lot of economic sense to reload 2 3/4" hulls to appropriately low pressures, especially if you're going to shoot a 2 1/2" gun a lot.

And we now know why CA is in dire economic straits. I thought it was just the politicians, but it appears to have short-circuited Wonko too. Must be something in the water.

It may or may not be the reason for the higher perceived recoil when shooting drastically longer shells than the chamber length, but here's my take on why it is. When the crimp opens and contacts the forcing cone, preventing complete opening, for a microsecond the entire load being propelled pushes against the forcing cone. Note that this is a FORWARD push. The load chokes itself down to get through the constricted case mouth as the gun is pushed ever so slightly forward. Then, after passing into the barrel the load passes without interference through the barrel and exits the muzzle where, and when, the laws of physics again cause gun movement. This time rearward. However, because of the slight forward push at the forcing cone the gun now has further to move as it recoils into your shoulder. This greater movement causes a harder "whack" when the recoiling gun meets resistance in the form of flesh and bone. This all occurs so quickly that we cannot perceive the forward movement from the short chamber, but I am convinced it occurs.

Some of us, being more recoil sensitive than others, can notice less difference than others. I can definitely feel the difference when a 3" shell is fired in a 2 3/4" chamber, but can't feel it when the difference is only 1/8".

One of the local idiots around here was, for a few days, fooling people into shooting a short barreled coach gun that he had gotten hold of. He was loading it with 3 1/2" magnums loads and betting them they wouldn't pull both triggers at the same time. I am not certain, but believe the gun has 2 3/4" chambers, certainly not over 3". He was forcing the shells into the gun and closing it before letting the (other) unsuspecting idiot shoot it. It is, amazingly, still sound. He never was.

Baby cartridge in a Brit toy gun or a pigeon load in a Perazzi.
That actually has nothing to do with the underlying physics. And like was mentioned it would be VERY difficult to acquire and factor in the acceleration rates of the shot charge. That does NOT mean that it is not the preeminent factor in perceived recoil as far as internal ballistics is concerned.

Obviously, gun fit can mitigate the nasties but plain old Newtonian physics still sets the parameters.
And that is not some JMO last I checked

And BTW, you guys are really funny with all the made up physics. And I thot the amplifier people were alone in the level of their nutso cosmic constructs. All y'all will have to reach some to equal them but you're on the way. Good luck on that

WtS

Uh, not an expert, Wonk, but, your analysis seems a bit light on the law of "conservation of momentum", that being a lighter object exhibits greater impulse than a heavier one receiving the same amount of energy. If I load my sub 5 lb. Italian folding 12 gauge ( Relax! we're talking a 3" chamber here-who says the Italians are cowards?) with one of your pigeon loads, I'm pretty sure it'll bend your remaining teeth in a way the P gun might not.
Only thing I can surmise about amps is, I'm betting you own several....
Best,
Ted

Nah. You got that all wrong. Its the pressure pushing forward to open the crimp that gives the gun the forward push, not going through the forcing cone
Seriously, I am reminded of a statement I once read from Julian Hatcher, "That sounds good IF you say it Real Fast, but it won't hold up to scrutiny". The gun doesn't swap directions in recoil, it moves reaward only.

You may well be right, Miller. But, if the pressure pushing forward gives the gun the forward push, as you say, and not the payload, then could not that ever so brief forward push from the pressure lend to some minute forward movement? I'm not proposing a big forward motion, only a tiny amount in a microsecond. The difference in the recoil is not much, either, as I perceive it, just enough to notice a difference.

Ballistics have been being studied for a mighty long time. No one seems to have discovered the reversal of motion & reported on it. Upon firing a conventional gun the expanding gases from the burning powder are exerting their pressure in all directions. As the projectile moves forward the gun moves backward.
I have fired a 3.5 rocket launcher of Korean vintage. There was a definite reversal of movement with this, "BUT" this is not a conventional firearm. It is a simple launch tube open at both ends, the "Rocket" is propelled by its exiting gases. There is a definite forward pull from the friction of the rocket moving down the tube & a slight reversal as it exits & the blast of gases strike the muzzle bell, put there to protect the firer. This is of course a totally different situation from a gun having a closed breech.
The shot charge is accelerating as it enters the cone & will continue to acceleraate as it passes through it. The gun also will continue to accelerate in the opposite direction. This will not present a situation where the gun would be moved away from the shoulder, to then return with greater force.

Well reasoned, Miller. I can see that. Don't think too hard of me for my theory. You wouldn't believe what the mind of a shotgun nut can come up with when he spends as many hours a day as I do in a tractor cab. You can listen to just so much of that drivel on the radio in a day without nutting up. Then again, there IS the occasional crow that gets a load of 6's out of my old 32" Montgomery Ward New Leader that rides with me.

Stan;
I would believe. Being 72 yrs old & having been interested in shotguns since around age 15 I have heard a lot of them. My very first shotgun which was all mine was an old, pre WWI J Stevens double. This gun had a through bolt for stock attachment.
Would you believe someone told me if I took off the butt plate & dropped a penny down in the bolt hole it would reduce the "Kick". Now even at that age I could see absolutely no effect a penny down the stock bolt hole could have on kick, but naturally had to try it. Just as naturally no difference at all could be felt, but as far as I know that penny is still there, just have no idea where the gun is.
If anyone ever runs across a J Stevens model 325 with a penny in the stock bolt hole it was probably mine. Actually this was a rather heavy gun & I was shooting regular field loads so kick was not an issue to begin with. I have though been rather skeptical of all "Magic Cures" for recoil ever since & found virtually all of them to simply exist in someones imagination, as you say shotgunners are an imaginative lot.

We, obviously, are speaking to different topics.

Unfortunately, like the guns, several is a long passed assessment.

WtS