I just had a Trijicon RMR mounted on my Sabatti. It is a 450cal. How should I go about sighting it in. At what distance should I try for zero? Any suggestions will be appreciated.

Buy or borrow a laser bore sighting device, place it one of the barrels, turn it on, and match the dots. Aligning the laser dot of the bore sighter with the dot in the Trijicon at 10 yards or more will get you on paper at 25 yds. From there, you are on your own. If you have a long hallway in your home for matching the laser dot to the sight, that will also get you close enough - this is what I did with my V-C 450,and it worked well.

My get on the paper routine for 50 yrs or so---paper plate painted black at 25yds, aim thru barrel until centered best ya can, bring the site, scope whatever on to plate. Now with the double we have all the regulation black magic so I might put 2 black plates, side by side, and center the barrels over them best I could. Never had a problem getting any type of site set up to hit the same black plate at 25. Then ya just walk the holes around until you are in the money.