My Wife runs a Walther Q4SF and I run the Q5SF. At a recent tier 4 IDPA regional, the chrono was a Lab Radar. Her gun ran 908,911,906 (134PF) mine ran 945,944,944 (142PF)
This is consistent with the variation I've seen in our other 4" vs. 5" 9mm 1911 pistols shooting exactly the same 147gr...