Jerry,
I actually start out with 3 in. hulls in an Ithaca 10 gauge with 2 7/8 in chambers. The I reload them again for a second firing in the Ithaca. Since I roll crimp, after 2 firings the case mouth gets a little rough so I trim them to 2 7/8 inches and use them in the Parker. After two firings in the Parker, I trim them again to 2 3/4 inches. Once they have been fired six times I either discard them or trim them to 2 1/2 inches for an old english single barrel...load them with rocksalt....and shoot cave crickets in the basement with them.
Love those 10 gauges.

Kirby if you are shooting your gun at targets the chamber mates will be fine. If you are going to hunt with it I would suggest black powder loads in brass shells. IMHO nothing exemplifies the killing ability of the 10's like brass shell loads.

Thank you for the input.
I fired her off tonight with RST light 1 -1/8 ounce loads.
What a hoot!
I need to document more detailed bore/choke dimensions as it throws a very tight pattern. I'm curious how my 7/8" soft 12-gauge reloads will react.
It will be Jan.1 before I get the Chamber-Mates. 10-20 ga set wiil be her soon to use up some 20-ga softly rolled stuff in the interim.
Great fun for Christmas. An added bonus is my letter arrived today and the old girl is still in factory attire. Thanks Mr. Bishop for the blazing fast research and processing of my request.
-Kirby