Another consideration, kane.
Barrel length doesn't equate to tight(er) patterns - choke does that (combined with a "proper" loading) & too, figure you'll "lose" 20 fps for every 1" less than a 30" barrel (usual published velocities - yada), but you'll likely see variations more than that in a box of shells.
Length of barrels has more to do with pointability & swing than anything patterning & velocity.
& a caveat to HSMITH's good post is a 3" 12 is nothing to sneeze at -
if you pattern properly. You certainly don't need a 3-1/2" 12 or a 10 ga to take turkeys plenty far (relatively speaking).
Depending on choke & loading (& how your shotgun is set up), pretty incredible patterns can be had with 2-3/4" 12s & certainly with a 3" 12. (Try a search on "card guns" sometimes to be very surprised). FWIW, I'm gettig incredible patterning/density in a 21" 12 w/Fed's 2 oz #4 turkey load - in one shotgun, & it really does suck in the other two (but I'm not using those for turkeys
).
I would never buy a SG based on what some new whiz-bang ammo will do. Likely, anything already proven &
much cheaper will do the same job.
Best bet = buy a gauge you think you'll be happy with & do all the things you'd want it to do, decide on a model/manufacturer, buy a few boxes of the type/size/quantity of shot to do that job & go pattern it to see if it will.
Sounds like you really want to get a 20 gauge for turkey hunting. My advice would be to get that 20, but then dedicate yourself to finding the best lchoke/oad to do just that.
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