I had the same problem, had to drill mine out. You can get replacement screws off of the Rohrbaugh web site, or you can do what I did, went to a local supply store and replaced the grip screws with stainless phillips flathead screws. The size you need is 1/4 inch long screws with 3-48 threads. When the screw size gets smaller, I think it is much easier to remove a phillips head screws than an allen head screws.