Fouryears ago, when I got my T/C Black Diamond XR, I chronograhed it againstmy regular Black Diamond. Both guns are stainless. The XR has a 26" barrel and the regular BD has a 22.5" barrel. Load was three 50 grain Pyrodex pellets with a 250 gr. Barnes Expander MZ. The longer barrel produced 105 fps more velocity. Note: I only fired one shot from each - no average of five or anything.