For the lighter bullets (180 and 200 gr) you can get some very interesting velocities. I’ve chrono’d a 180 Hornady at 1650+ out of a 5” bbl M 629 with no pressure signs. Quick Load says 17.5 is about max. Mine is a bit lower but still has some serious thump. As for 200 gr bullets I was using around 14-14.5 which also has some serious thump.