S&W started offering porting on their guns, but not the Magnaport style. They moved the front sight back and machined an oval port crossways going down from the barrel rib, forming an expansion chamber and baffle.
Was considering getting a .44 set up that way, so I picked up a dirt cheap 13 that was badly pitted, finish worn off, and the lockup was terrible. In other words nothing to lose. Milled a port like S&W had to test it. Lost the front sight, but intended to install a brass shotgun bead there. Shot it, and found I absolutely did not like the port. Probably should have milled it off and made a snubby out of it. But instead gave it to a friend for his son and said it needs work, and suggested making it an object lesson in how to fix up an old revolver. Not sure what he did with it, forgot to ask how it turned out. It was not beyond repair, but mainly needed a new hand fitted plus maybe an oversize cylinder stop. The outside had nothing to lose for a kid to practice polishing it.