I've never actually chrono'd factory rounds out of one of my pistols, but my Contender load book gives velocities out of a 10" Contender... my Raging Hornet had a 10" barrel originally, & if I remember correctly, I lost less than 100 fps on my handloads ( more like 30-40 ) in the revolver, with the extra cylinder length, & a barrel cylinder gap... new format for that gun has a 6" barrel, but a 1 in 9" twist, & a tighter barrel cylinder gap