doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Longer shells in Short Chambers

I wouldn't know what is causing the difference either, but since you do notice such a marked difference then I think you are right to steer clear of those loads. It would be interested to see what happens to your perceived recoil with those same AA cases loaded differently. Or with a close replication of that load in a shorter case.

(I'm wondering if it is something particular to that case in your gun's chamber causing the change. Or if it is attributable to the other differences between loads.)

Certainly understanding perceived recoil is much more complicated than calculating foot pounds. Any number of things come into play from powder burn rates, to gun fit, to barrel harmonics, to sound, etc. etc. to quote Churchill (I think) "It is a riddle wrapped in a mystery inside an enigma."

I also think recoil expressed merely as foot pounds is not adequate to understand recoil-damage to a gun. Two loads generating equal muzzle velocities with equal ejecta (same calculated recoil) may effect the gun itself differently...

"I also think recoil expressed merely as foot pounds is not adequate to understand recoil-damage to a gun. Two loads generating equal muzzle velocities with equal ejecta (same calculated recoil) may effect the gun itself differently..."

And exactly how would that come about? JL

Lots of ways.

- Damage to guns during recoil is effected at least to some extent to vibration during recoil. Simple measuring muzzle velocity is not going to determine how the load "shakes" the gun.

- muzzle velocity tells you nothing about how the load got to that velocity. I imagine that a load reaching its muzzle velocity rapidly will effect the gun differently than one that accelerates the load to muzzle velocity more smoothly.

- Think push vs hit - perhaps when it comes to felt recoil the microseconds difference is time to reach peak speed may not be noticable, but small canges in speeds of accelerations can have big changes on damage to mechanical things. (This in part is what is happening when you use rubber to dampen the blow of something. The total foot-pound force is not changed, but the time it takes to deliver that force is...)

- and on it goes. So much happens between the breech and the muzzle. If someone wishes to claim that only muzzle velocity (and ejecta mass) determine the effects of recoil I would think the burden of proof is on them. They would have to explain why a charge reaching (near) muzzle velocity in 6 inches affects the gun exactly the same as one reaching that velocity in 15 inches...

- Even chokes have a minor impact on muzzle velocity...

Oops double post

Or said more simply - It is my intuition that it is peak force rather than total work that matters to the gun. measuring muzzle velocity and ejecta measures how much recoil "work" (foot-pound force) was done but it doesn't measure how much recoil force was developed. No?

Buy a slip-on LimbSaver pad and be done with it. :rolleyes: I believe most Walmarts carry medium size as regular stock item.
PS. That's just to take a sting out of an "ass kicker". NP.Read info on ammo box before stuffing it into them chambers! Obviously old gun with "short chambers" was not designed for 70mm shells.

I very rarely comment on such issues, but this is the exception.Why Oh Why do you spend so many column inches on trying to justify what to my mind is crass stupidity.It is my belief that you could load a perfectly adequate load to suit most events you are likely to have to address with a case length that is correct and a load that is comfortable.For instance where are the questions on shooting 75mm/3" shells in 67mm /2 3/4"chambers
Is this why you seem to have no faith in Damascus barrels?
How many of you have fallen in the River despite warnings from Momma? Or had burns from playing with fire?
It reminds me of the weeing up the wall contests at junior school. ( Ole big dick never did get the girls

i don't think burrard ever advocated anything ranking as crass stupidity, or any other kind of stupidity. and - going off memory as i don't have his books right in front of me - he actually stated the change to 2-3/4" shells was precipitated by the folded crimp. the shorter loaded length reduced the payload capacity and to get that back they lengthened the opened shell which gave a comparitive loaded length to a 2.5" roll crimp. all of which 2-piper explained in english that shouldn't be that hard to understand.

and nobody discusses shooting 3" shells in 2.75" chambers because in both cases - except for some possible really arcane examples - they're both folded crimp and also, the typical 3" shell is a magnum and thus violates the "same load as the gun was proofed for" caveat. one would not shoot a 2.75" magnum in a 2.5" chambered gun but a 2.75" shell that was loaded to same specs as a 2.5" shell the gun was proofed for is OK. there's 2 criteria that have to be met and the first one is "....same load...".

roger

I believe in shooting what it's chambered for.

Do you guys that like to shoot longer shells in your short chambers think you're getting as good of performance out of your gun as you could be by matching the ammo to the chamber length ?

In other words do you think your gun will wee higher up the wall with a longer hull.
L.F.

Note, that since the introduction of the fold crimp, nearly all British shells "Factory" loaded for the 2½" game gun have been put up in cases longer than 2½". Also note, as has been mentioned here on numerous occasions, several US makers intentionally chambered their guns about 1/8" shorter than the shells they were meant to fire for the purpose of "Improved Performance". In both cases the shells were longer than their chambers, & they were the shells the guns were "Meant To Fire". A thorough understanding of the reasons is far better than blanket statements, which is the purpose of this board.
Miller