Dave, I can't do that wrote:
On Jul 5, 8:45 am, "BillM" wrote:

Hi Bill,


Any good reason not to make a quick D reamer for the job?


I would check the working pressure of the 2-9/16" as the 2-3/4" will
have a lot more grunt to push out the larger load. The barrel may not
be designed to handle the CUP of 2-3/4".

Dave

I wouldn't give it a second thought.

Shotshell pressures are all in the 6000 to 10,000 psi range, and have
been for about ever. Lengthening chambers has been a stock in trade for
the smiths for about as long. The longer shells are mostly to deal with
the newer styles of wads that replaced the felt washers the were used
for eons. The payloads are not appreciably larger, typically on either
side of an ounce.

If you think the barrels and action will take it, have at.

Good opportunity to build a nice long forcing cone onto the chamber,
if it is not already.

FWIW, there were some write-ups done a while back in Double Gun
Journal, on the pressure results from shooting 12G 2 3/4" shells, in old
2 1/2" chambers. The rise in pressure that came about was far less than
had been predicted, and came as a bit of a shock to the hand-wringers
that were predicting a disaster.

Cheers
Trevor Jones