need longer scope mount or? eye relief?

Leatherwood has their LER scope, long eye relief, that starts its eye relief at about 13''. Its a popular scope for Mosin shooters and allows it to sit a little more forward.

Hello, Im a collector of 31/30 rifles, and have at least 40 different ones of all variations. I am using the mount that is put in place of the old iron sight. but the rail dosent get the scope back to the proper closeness required to get an open view. My scope is a busnell elete DOA 3X9X50 but I dont want to drill holes in the reciever if I dont have to. So Im wondering if any of you guys know an scope with a 6" relief or a longer scope rail of some type, or an alternate to having to drill out the reciever. Thanks