The Magpul MBUS Pro Rear is an all-steel dual-aperture folding backup iron sight for AR-15 and M4 rifles, clamping to any 1913 Picatinny top rail.
The Magpul MBUS Pro Rear Sight (MAG276) brings all-steel construction to the rear half of your iron-sight equation. The dual-aperture design flips between a large ring for fast, close work and a small aperture for precision at distance — the classic combat configuration, executed with machined precision. Windage adjusts tool-lessly with positive, audible clicks, so refining zero at the range needs nothing but your fingers.
Folded, the sight sits extraordinarily low and snag-free; deployed, it locks up without play and returns to zero shot after shot. Paired with an MBUS Pro front, you get a sighting system tough enough to serve as primary irons on a dedicated build — and dependable enough to bet on when an optic goes down.
Key Features
- All-steel construction: built to take what polymer cannot
- Dual apertures: fast ring up close, fine aperture at distance
- Tool-less windage adjustment: crisp, positive clicks
- Ultra-low folded profile: clean under optics, snag-free
- True return to zero: deployment after deployment
Compatibility & Fitment
Fits 1913 Picatinny top rails on AR-15/M4 pattern rifles, at the rear of the receiver rail in the usual backup sight position. Make sure there is clear rail behind your optic or mount before you buy, and that the front and rear sit on the same rail plane. It pairs with any MBUS Pro front sight; elevation is normally set on the front sight, so zero the pair together.
Technical Specifications
Platform | AR-15 / M4 |
Type | Dual-aperture flip-up rear sight |
Material | Steel |
Finish | Black |
Mount Interface | 1913 Picatinny top rail |
Adjustment | Tool-less windage |
US Shipping & Support
Shipped from D&R Sports Center in the USA with fast, tracked delivery. Questions on fit, mounting or which model suits your setup? Our team is glad to help before and after your purchase.
Frequently Asked Questions
Where does the MBUS Pro rear sight fit?
It mounts to 1913 Picatinny top rails on AR-15/M4 pattern rifles, at the rear of the receiver rail in the usual backup sight position. It pairs with any MBUS Pro front sight, for example the MBUS Pro Front Folding Sight. Make sure there is clear rail behind your optic or mount before you buy.
What is the dual aperture for?
The MAG276 gives you two apertures: a larger one for quick, close work and a smaller one for a more precise sight picture at distance. You switch between them by flipping the aperture over. That is the main difference from single-aperture backups, and it is a genuine benefit if you use irons for more than emergencies.
How do I zero the windage?
Windage is tool-less, so it can be adjusted by hand at the range without carrying a sight tool. The sight body is steel throughout, which is why it feels dense compared with a polymer flip-up. Elevation is normally set on the front sight, so plan on zeroing the pair together.
What else do I need to complete the set?
You need a matching MBUS Pro front sight, and the front and rear should sit on the same rail plane so the sight picture lines up. The MBUS Pro line is black steel only, so there is no color to choose; the polymer MBUS rear is the lighter alternative.
