This is how I inlet a Butt plate. I concentrate on in letting the upper part first to get it level and centered following the line of the barrel line. Then to inlet the crescent part I grind off the sides of the head leaving the slot of the screw intact and screw it into the stock where the final screw is going to go. Then use in-letting black on the inside of the crescent shape (sparingly) applied with a toothbrush. Slide the butt plate forward until it engages the ground screw in the screw hole and until it leaves marks on the wood of the crescent area. If you tap the plate with a rubber mallet, do it softly. Remove that wood. Keep repeating this until the plate fits perfect. The ground off screw is there to guide it the same every time. I hope this helps