Greetings all from "Longrider" , a new member, and I have a question regarding muzzle velocity. Out of curiosity, I chrono'ed various 9 mm ammos - Winchester, Speer, Federal, Underwood, Blazer-out of my old P225, 3.7" barrel ,and compared that with the 4.7" barrel of my new P320. Results were not what I expected. The 3.7" barrel of the older P225 produced velocities marginally better than the new 4.7" of the P320. With the "ProChrono Digital", I recorded velocities in this 3.7" to 4.7" comparison. Examples : The Winchester 115gr. JHP velocity was 1162 out of the 3.7" P225 & 1142 from the 4.7" P320; The Hornady XTP 115 gr. was 1170 from the 3.7" & 1129 from the 4.7"; Federal HST 124gr was 1166 in the 3.7" & 1160 in the 4.7"; Speer GD 124gr+P was 1201in the 3.7" & 1185 in the 4.7". Is it funny to you that the 4.7" barrel (P320)comes in with lower (marginally) or equal only to the 3.7 " barrel (P225)? Is some minor deviation/flaw present in the new P320 or something else at work ? I'm trying to understand how a longer barrel (by one inch) pistol ,new, can come up with slower velocities than the older P225. Strange to me. Ideas gentlemen ?? Thanks from a newcomer