I have used the 627 with a contender pistol barrel in 357Max. Due to the forcing cone design of the original contender barrels, I load extremely long with barely more than the gas check in the case. I have been using VV N120 at 24.5 gr and getting about 1600fps from a 10inch with a muzzle brake. I would expect probably 1800 or a bit more from your longer barrel.
I use this wonderful boolit in my 12″ Contender barrel that was 357 mag but was reamed out to Max by Mike Bellm. The barrel wears a custom made compensator and shoots wonderfully with a stiff charge of IMR4227. I use a Pride-Fowler scope that has hash marks set up for 44 mag, but the Max shoots so much flatter than the 44 the lines dont mean much, especially at 200 yds! Lol