The Challis slotted grip screws are slightly shorter than most standard slotted grip screws. I see this as an advantage, because some bushings are shorter than normal, this causes a longer grips screw to thread below the bushing into the magwell and trap the magazine. That's not an issue with the Challis shorter grip screws. I've had a difficult time in the past just trying to locate slotted stainless grip screws, so it's good to have a source to get them.