I ran 180, 200 and 240 gr XTP in my 629 4"
Max loads of 296.
Accuracy was fine.
Blast was nasty, and there was some flame cut of topstrap (gun didn't have any when I got it).
No big deal.
Sold it to get a 6", then went 8 3/8" and back to 6".
Think the 4" the most fun though. Short sight radius.........was 50 yards and in rig for me.
Miss that gun