You might review the chamber diagrams in TPS, which illustrate the tapered chambers.

Charlie, those are chamber measurements. I think, but not sure, chambers get .005 smaller per inch. If so, that's in the ball park. Paul

The Remington era specification sheets reproduced on pages 164 - 169 of The Parker Story call for a 10-gauge with a 2 3/4 inch chamber intended for the standard 2 7/8 inch shell, 12-, 16-, and 20-gauges with a 2 5/8 inch chamber intended for the 2 3/4 inch shells, 28-gauge with a 2 13/16 inch chamber intended for the 2 7/8 inch shell and the .410-bore with a 2 15/16 inch chamber for the 3-inch shell. Other chamber depths optional.

Never know what a person might learn about Parkers if he just reads TPS.

Actually this table is on page 524 not 514...if you can, please post the chart on page 519. That may shed some light where the 2 1/2" comes from, and the .005 per inch chamber taper that Paul refers to. Thanks, George

No Jent. It does not and is not intended to . That would be a different question and there is no indication that anybody has asked anything about 1870's vintage lifter action guns and brass shell barrels

George please be my guest and post any photos you deem appropriate

Thanks to you all for the responses. An impressive amount of knowledge and information and I appreciate it. Mike

im straight on the chamber measurements now....its slow to soak in sometimes for me..thanks fellas.... charlie