no- he is saying-for example - an unfired 2 3/4 12 gauge shell will fit in a 2 5/8 chamber.

the crimped portion of the shell has to fit within the chamber when it has been fired - otherwise it opens into the forcing cone and there can be pressure implications

a 2 5/8 shell is 2 5/8 AFTER firing (or brand new before being loaded the first time)

Thanks for the clarification.

A simple, easy to make and accurate chamber gauge
 

A simple, easy to make and accurate chamber gauge:

Using a fired empty hull, preferrably plastic, squarely cut the crimped end off and make another square cut near the metal base. Clean off the cut edges. Measure the length. This is your gauge.

Insert the gauge into the empty chamber until it stops at the forcing cone. Use a small scale to see how deep the gauge is and add that depth to the length of the gauge and you have the chamber length.

Make for other gauges as needed.

I might add that I have a friends 10 gauge underlifter and it has 2 3/4 inch chambers. A "PARKER BROS. WEST MERIDEN, CT 10 A" 2 3/4" brass shell fits nicely but the more common "PARKER BROS. MERIDEN, CT 10 A" 2 7/8" stops 1/8" short of going all the way in.

Hope this helps.

Bill Jolliff

Someone (forgotten who) described taking a small machinist's rule (squared end forward) and inserting it into the chamber, touching the chamber wall, with good light coming from the muzzle end. When the rule begins to enter the forcing cone, the side of the rule will begin to separate from the chamber wall. When it does, look at the measurement on the rule. Bingo!

Not necessarily. Parker routinely cut their chambers 1/8th inch short to achieve a better gas seal for the fiber wads used in period ammunition so a chamber that measures 2 3/4 inches would be appropriate for use with 2 7/8th inch shells.

That is true for guns chambered for paper shells. Guns chambered for the B brass shells should have a chamber exactly the length of the brass shell.

How were the brass shells closed? I doubt they were crimped.

water glass (sodium silicate)

Used as a glue around the edge of the over shot card

Modern military brass shells are slightly rolled over the edge of the over-shot wad --

http://img.photobucket.com/albums/v3...ps63e526ba.jpg

but 120 years ago our Nimrods sat around duck camp in the evening reloading their brass shells and sealing the over-shot wad with waterglass, like this W.R.A. Co. No. 12 RIVAL --

http://img.photobucket.com/albums/v3...psc41b8e4c.jpg

Well today I fired my 10 ga Parker for the 1st time. It was also my 1st time firing any 10 ga. I want to thank my friend John for making it possible. Now the long journey of restoration begins.