So there's absolutely no wiggle room there. There aren't any mods that can be used for more than one weapon? You'd figure something like a scope for a magnum would be interchangeable or something.
Sorry but you should be warned, theres a Rant incomeing to you for saying that!
First off a pistol scope will have eye relief that corresponds to focus at an arms length grip hold of the pistol, a rifle scope will have more like 3-5.5 inches of relief depending on model. Trying to mount a scope that was made for a rifle on a handgun or a handgun on a rifle will cause all kinds of problems with the focus that often cant be fixed by the average end user even if they have the tools because the scope was not designed with that kind of shooting in mind in the first place.
(thats not counting a "scout scope" thats designed with forward mounting on a carbine or ahead of a rifle action., while they are a bit more interchangable between"cabines" and rifles, there not as good on a rifle as a dedicated Rifle mount, and Ironicaly are often far more "Fragile" than a rifle scope would be if you tried to get it to mount on a handgun!)
Second Pistol scopes are designed to be lighter and (oddly enough for being lighter) tougher than rifle mounted scopes as the scope has to deal with the shock of recoil, especialy on higher power handguns like the .44 and the .50. Even some of the early high end handgun scopes could not deal with the recoil of high end handguns for very long.
Third Pistol scopes are designed with the shorter range of a handgun in mind in the first place, making them kind of useless on a longer range rifle
4th (granted this is more of a one way street) a lot of Rifle scopes just will not mount properly on a pistol in the first place,
5th or probably 4.5th pistol scopes are nowdays deigned to have a minimal impact on the "balance" of a handgun, the same is
not true of mounting a rifle scope to a pistol!