Clip-On Night/Thermal Alignment on Picatinny — Basics That Prevent POI Shift
Keep point of impact stable when adding a clip-on. Level the rifle, use a true Picatinny datum, set repeatable slot positions, and confirm with a short daylight check.
Why alignment matters
Clip-ons ride in front of the day optic. If they’re not square and repeatable on the rail, small misalignments become point-of-impact shifts—especially at distance.
Rail & slot discipline
• Use a rigid Picatinny base that’s straight to the bore (e.g., 0 MOA or 20 MOA as your build requires).
• Pick exact rail slots for the clip-on and mark them (paint pen).
• Seat the mount fully forward into the slot before tightening—same pressure every time.
Level in position
• Level the rifle to the bore line first, then set the clip-on so its housing is visually square.
• Tighten evenly to spec; avoid “one-side tight” that twists the mount.
• Recheck level after tightening and after a few shots.
Quick confirmation routine
• In daylight, shoot a 3-shot zero group without the clip-on.
• Mount the clip-on on your marked slots and shoot another 3-shot group at the same POA.
• If there’s a shift, note direction/magnitude, re-seat once to verify, then record the offset if it’s consistent.
Good practice
• Keep rail and mount faces clean and dry.
• Don’t hang accessories that flex the rail ahead of the optic.
• Record slot positions, torque values, and any observed offset on a setup card.
Next steps
Review 20 MOA vs 0 MOA Scope Bases, Chassis Setup 101, and Scope Tracking & Return-to-Zero Checks to keep the whole system repeatable.