22/45 Fan said:
Weaver #12's are the correct scope bases. As noted they are not rails.
Yes BUT! You may not be able to mount your scope depending on its size. The distance between the front bell and the rear may not allow you to move the scope far enough forward or rearward. Your eyes, the scopes focal length and other factors can come into play. Some of that can be taken care of by using offset rings. The rail gives you a little more flexibility on where you mount your rings.
As an example I have a leupold 2x7 rimfire scope mounted on my American compact 22lr using #12 bases. The distance between the front and rear bell on the scope is 5". I would like to move it back another 1/2" but the front scope ring acts as a stop.
Sorry I forgot to mention that how YOU hold your rifle effect this also. you can move your head forward or back to get a clear sight picture but if it places you in a incorrect position it can negatively effect your shooting. And one last thing what is a standard scope? I suspect you will get different answer from the others here. Rimfire or big bore scope, fixed or variable, compact, 1" or 3/4" 7/8" tube, adjustable objective lots of variables. If you don't mind shopping online you can call brownells. They have a tech support crew that can pretty much tell you need to mount whatever scope you have on your gun. Most if not all of them are gunsmiths and everyone I have talked to have been friendly and helpful. Brownells.com or 1-800-741-0015 Don't forget to ask for a free catalog. Hrs. of good reading there.
Can anyone else add or clarify what I have said?