Pistol Scope Mounts

[Remo]

I'd like to buy a red dot sight with a mounting system that can be used on my P3 and with a Crosman custom shop pistol (Crosman steel breech) when it arrives.  The problem I'm having is that I'm not sure of the size of their scope rails. According to Crosman, the steel breech is a 3/8" dovetail.  Anybody know about the P3 rail?

Eric