I use riflescopes on several of my pistols.
There are two considerations. One is if the hold you use allows proper eye position for the scope you're using.
the other is the need for a strong enough hold so you won't wack your forehead or eye from the recoil. That probably won't be a problem with a 22-250 but it's something to consider.
Try a google images search on "riflescope pistol silhouette" for some examples.
It's my understanding that the XP-100R (rear grip with magazine) action is the same as a Rem Model 7 except for marking and pistol FCC registration.
The XP-100 (mid grip) action was the same as the Rem Model 600 but with no magazine cutout, marking, and pistol FCC registration..