I believe 7600 carbines (18.5" bbl) were only mfd in 30-06 in select years. All other calibers 22" non-carbine. Older 760 carbines were mfd in other calibers (35, 280, etc.) You don't need a gunsmith to improve this 870 trigger group. Take 2 pins out, pull trigger cassette out, replace springs, pop back in, 2 pins in. <10 min. and shipping costs more than the springs. Brings groups down to <1" with quality ammo. There's a booklet available for 760/7600 takedowns. The carbines listed on GB outside of 3006 were custom-made by cutting/recrowning the original bbls, etc. but I've contemplated doing same on my son's 22". After this past season, he asked if we could cut the bbl to make it more like mine (that he used to bag several deer as a young kid)! lol I think 20" would probably be the best compromise in quick-pointing and velocity retention/max distance, if you were contemplating cutting down a 22" (much more common.)I am only looking for a 7600. I watch everyday with no luck. The only Carbines listed are already sold