While I have great respect for the knowledge of some here who use/have used chamber inserts to shoot a smaller gauge shell in a larger gauge gun, the reason(s) for doing so are totally lost on me. Inserts are terribly slow to reload, unless you've got a bunch of them that you can swap while shooting, and even then the aggravation of pushing out the empties from the tubes, etc., is just too tedious for me. I shoot short tens, Don, and load them to fit the gun (2 7/8"), but for the life of me I cannot see the reasoning in wanting to shoot a smaller gauge shell in a gun. I know this is a personal matter, for many of you enjoy doing so, obviously, but if I can't shoot the proper shells in a gun I'm just gonna get rid of it and get something with which I can.
Using full length tubes in a 12 ga. comp gun is a different matter, and is usually done by serious competitors by having a set of carrier barrels made that, when fitted with the sub-gauge tubes, will weigh the same as the 12 gauge barrels. This is to try and approximate, or equal, the shooting dynamics of the 12 when competing in sub-gauge events.
Please understand that I am not belittling anyone who enjoys this practice. In fact, I admire those who have the patience to submit to this kind of tedium while shooting. If I want to reload that slow I'll use my muzzleloaders.
