The Trijicon RM66 RMR Mount for ACOG (SKU AC32029) is a machined aluminium piggyback mount that fits a Trijicon RMR or SRO red dot sight on top of an ACOG rifle scope fitted with mounting bosses, giving a magnified primary optic and a 1× close-range sight on one rifle.
A magnified ACOG is superb at distance and slow up close. Adding an RMR above it means a target inside 25 metres is taken with a head lift onto the dot rather than a scope change, which is why the piggyback arrangement became standard on service rifles. The RM66 bolts to the ACOG's own mounting bosses, so the red dot indexes off the scope body rather than needing rail space of its own.
How It Compares
ACOG boss patterns differ between models, so match the mount to your scope: this is the RM66 (AC32029), and the other option is the Trijicon RM35 RMR mount for ACOG (AC32007). If you are unsure which your ACOG takes, contact us with the model before ordering. Mounting on a rail instead? The RM33 low Picatinny mount (AC32004) and RM34 tall Picatinny mount (AC32005) carry the same optics. Browse all red dot sight mounts, our Trijicon ACOG rifle scopes, every optic on the RMR footprint and our offset and piggyback red dot sights.
Ideal For
- Civilian Service Rifle shooters running an ACOG who want a 1× option for close targets
- Practical rifle and 3-Gun stages mixing long and short-range targets
- Straight-pull rifle builds pairing magnification with a fast backup dot
- Airsoft rifle builds replicating a service ACOG and RMR pairing
Key Features
-
Fits Optic: Trijicon RMR and SRO red dot sights (RMR footprint)
-
Mounts To: Trijicon ACOG rifle scopes fitted with mounting bosses
-
Position: Piggyback — the red dot sits above the ACOG for a head-lift transition
-
Material: Machined aluminium
-
Hardware: Mounting hardware included
-
Origin: Made in USA
Technical Specifications
| Product Type |
Piggyback red dot sight mount for ACOG |
| Fits Optic |
Trijicon RMR / SRO (RMR footprint) |
| Mounts To |
Trijicon ACOG with mounting bosses |
| Material |
Machined aluminium |
| Country of Origin |
Made in USA |
| SKU / MPN / UPC |
AC32029 / AC32029 / 719307609198 |
What's Included
- Trijicon RM66 RMR mount for ACOG (AC32029)
- Mounting hardware
Warranty
Covered by Trijicon's manufacturer's warranty. Keep your order confirmation as proof of purchase; we handle warranty claims for you from the UK.
UK Delivery & Support
UK-stocked and dispatched tracked from our UK warehouse — no import duties or customs delays — backed by UK-based support and Trijicon's warranty.
Frequently Asked Questions
What does the Trijicon RM66 do?
The Trijicon RM66 (AC32029) mounts a Trijicon RMR or SRO red dot sight on top of an ACOG rifle scope that has mounting bosses, so the rifle carries a magnified primary optic and a 1× red dot for close targets at the same time.
What is the difference between the Trijicon RM35 and RM66?
Both are piggyback RMR mounts that bolt to an ACOG's mounting bosses, but they suit different ACOG models and boss patterns — the RM35 is AC32007 and the RM66 is AC32029. Check your ACOG model against the mount, or contact us with the model number and we will confirm which one you need.
Which red dot sights fit on the Trijicon RM66?
Trijicon RMR and SRO sights, and any other red dot sight built on the RMR footprint. The optic and the ACOG are both sold separately.
Will the RM66 fit any ACOG?
No — it fits ACOG models that are supplied with mounting bosses on the scope body. ACOGs without bosses cannot take a boss-mounted piggyback mount, so confirm your scope before ordering.
