2 3/4" shell in 3 1/2 " chamber

[Scoutfish]

Last night, my son, my nephew and myself went to a local volunteer fire dept turkey shoot.
My nephew and I both won a turkey last week and was hoping my son would get one this time...which he did.

Anyways, my nephew borrowed a break action shotgun that could hold 3 1/2 " shells to take to the turkey shoot.
Old gun, can hold 3 1/2 " shells, has a 36" barrel. Weighs at least twice as much as the other guns we used last week
which have 28' and 29 1/2 " barrels

We both tried it one shot each at which time we went back to the break opens we used last time.

The pattern was horrible and wide.

We figured this gun would have a nice tight pattern due to the long barrel and choke. Couldn't tell you how much choke it has,
but the end of the barrel is noticably smaller than the chamber end.

So we are wondering what went wrong?

Is it because the shorter shell didn't have the extra powder behind it?

Is it because the shot has more room to bounce around and loose thier tragectory?

Is it because the shells are just basic shells?

The shells are handed out by the turkey shoot officals and are the cheap ones you buy at Wal-Mart .
100 shells for $23.99 ( it's a fundraiser turkey shoot)

" Remington gun club
3 - 1 1/6 - 7 1/2
2 3/4" - 70mm

So...are we close to guessing what happened? Kinda? Sorta? Not even close?

[mnslayer]

shotguns chambered for 3 1/2 should shoot 2 3/4. the gun is designed for heavier loads and this could effect the pattern. without knowing the choke of the gun hard to say what happened. This is why turkey hunters check the pattern on their shotguns by shooting different loads. some shotguns like different shells like some rifles like different bullets.

[Dan Salmon]

If you think about it, there is an extra 3/4" of chamber and the forcing cone to traverse without support from the shell casing. As was said before, each firearm is law unto itself, but if you look at the guns specially made for the clays games, they are all 2 3/4" chambered.