What size screws for Allchin base on a 22/45? I may have goofed big time.

[Canman]

Ok so my C-more gets a little loose at the range. I go to tighten the base up and I have the wrong screws in and strip out the mount holes! I have used the screws that came with the rail on the pistol and they are not long enough. Looks like I should have enough thread left to get a good hold without having to rethread the pistol. Anybody help me with the correct size screws? Shooter Connections closed for holidays and I need to get these so I can get my seven year old daughter back up and running.