I have the Wheeler tool also. It is a very good sight pusher that will do "hard to drift" sights. I've used it on some that are known to be tough and so long as you make sure the slide is lined up perfectly parallel in the tool it will work fine. With some particularly tough sights I have had to use a small brass hammer to tap the steel pusher of the tool itself after first lining the slide up and putting pressure on the sight. Not much of a tap, just enough to get the sight to break free. If you cut some strips from a camping cutting board it will help you to protect the finish on those slides with tough to move sights.

I have not used the Wheeler on my Kahrs because I only have one which needs new sights, and it is one of only 89 MK9 Elite 2000 Elites that Kahr produced and sold to the public. It is finished in black Roguard on the slide and frame and I haven't yet worked up the courage to risk marring the slide. Also though finding night sights with the old dovetail cuts is not easy and that too has "saved" me from taking the plunge and trying it.

But on those that I have used the tool on it has worked very well, and it is one of those that will do both front and rear sights, another plus.