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Barrel length is a consideration with any handgun. All things being equal, barrel length makes a difference in so far as utilizing full performance of any round.
While a pistol contains the round in the barrel itself, with a revolver, the round is held for firing in the cylinder.
I have beside me, my S&W model 642, which has a nominal 2" barrel..while the cylinder itself is 1.5"..
Is not the 642 ballistically equal to a 3.5" barreled pistol? Yes, the pistol will have benefit of a longer sighting radius, but isn't the cylinder considered as part of the barrel when considering ballistics?