I am in the process of setting up an XT on one of my semi auto Remmys...I am going old school with leupold base/rings...so far, haven't come up with a good place to mount the UNV 20 IR...the best spot I have come up with is...hand held 3 ft above, 1 ft in front of and two feet to the left of the scope (had to have help)...otherwise it washes out the bottom half of the scope....bearclaw suggested below the front of the muzzle...got to try that option soon....but the factory illuminator seems to work ok in my limited experience.

Yessir, the factory IR on the XT is fairly decent at short range. The UNV 20 IR just makes a much prettier picture...and from short range up exceeding the ability of the scope.

I have one if those mounts for under the barrel. With an old school Remmy I sorta like that idea (limited choice), though I didn't like it on anything else (seemed to always get in the way of trying to rest the rifle).

Post us a pic when you git 'er all rigged out...