Inletting a Model 99 Aftermarket Stock

I'm in the process of inletting a new laminated stock and forend for my pistol grip Model 99F. This is the first time I am attempting such a thing and this chore is going reasonably well. My biggest problem right now is I have a small and consistently uniform gap (approximately the width of two pieces of paper) between the wood and the rear end of the receiver. Am I correct in assuming that this is the most critical area in the fit and what will prevent the stock from splitting under recoil? It looks as though there is a "problem area" that needs to be sanded and then the stock should fit perfectly, but I can not find the problem area. Any suggestions? I am reluctant to just keep sanding away. Would it be wise to just go ahead and glass bed the entire stock and forend where the wood meets metal? Any suggestions are greatly appreciated.

Dave Sinko

Have no experience with a 99 but I mark either the wood or metal
with chalk, slip back together and see where the transfer of chalk is.
Sand till I get even contact. It's slow but works for me.
Hope it helps.
Kenny