Clarence, I'm new to Parkers(jsut got my first vh, 16ga, thats gonna get tarted up
) But not new to older guns. With regard to chamber lenght, I have had chambers lengthened with the idea that I'd be able to shoot standard ammo out of them. What I have found is it's not that much fun to shoot "sharp" modern loads out of light game guns. When I buy Ammo, I order RST stuff from Alex(he'll ship right to your door), in 2 1/2" configuration. Either 3/4 or 7/8's oz. When I reload, I load 5/8, 3/4 and 7/8 oz stuff for all my guns, 12's, 16's ,20's and 28's(3/4 is the max for the 28, and the 12 wont get a 5/8), both older and modern. Good for the gun, and good for my shoulder( and I;m not a tiny guy with flinch issues). Cost for the RST are about 10.00 a box, my reloads are about 3.50 now that lead has come down.