I've got an AirLite Ti, 44 special, that I got when they first came out. Now, of course, it's no longer made. I've carried it for years as a backpack/hiking pistol, with 180 grain bullets and/or snake shot.

Using some heavier bullets now - 255 grain - and notice how really high the point of impact is, even though I have factory sights on it.

Even at 7 yards with the rear sight cranked all the way down it's shooting 5 -6 " high. At 15 yards, it's easily a foot high.

Looks like it needed a higher front sight ramp. Anybody else have one of these and noticed something similar? Or maybe with the 625 Mountain Gun?

Curious....

I have the 625 Mountain Gun in .45 ACP and have not had the problems you are experiencing. I use 230 to 260 grain bullet weights. Your best bet may be to contact S&W to check on the availability of a higher front sight.

It would be easier to change the blade on your rear sight. Measure your current blade and then buy the next lowest one. It is fairly easy to change out the blade. Here's how to do it.

http://www.youtube.com/watch?v=E_sDPh18Z08

When I load my M629 Mtn Gun with 300 gr Federal Castcore for bear defense I have to crank the rear sight all the way down. It strikes point of aim at seven yards, but it's out of the black at 50 feet and half off the paper at 25 yards. If I planned to use such loads for anything but close range emergencies I'd probably get a taller front sight. In your case even with a taller front sight you may end up stuck with something less that a 255 grain bullet.