Since this has not been mentioned; check the base of the vent rib just at the rear of the front sight. You may find two small oval shaped holes. If you do find them, see if the barrel has a ring of holes about an inch from the muzzle. The factory says that you should not use cast as there is a chance the holes could strip lead from the bullets and become plugged.
My 44 came with a ported and nonported barrel when I bought it new in 1979/80.
There are other threads in here as well about the porting system if you search. I think it does work to some extent; but not as well as a heavy scope and base.
