Magpul MBUS 3 Sight Rear for AR-15/M4
Mix and match across the range: 2 items save 5%, 3 save 10%, 4 or more save 15% on your whole basket.
Fits 1913 Picatinny top rails on AR-15/M4 pattern rifles. Pairs with the MBUS 3 Front (MAG1166).
Not sure it fits your rifle? Ask us before you order
The Magpul MBUS 3 Rear is a polymer dual-aperture flip-up backup iron sight for AR-15 and M4 rifles, clamping to any 1913 Picatinny top rail.
Dual apertures, constant-tension deployment and tool-less windage — the MBUS 3 Rear is the smartest polymer backup sight made.
The Magpul MBUS 3 Rear Sight (MAG1167) pairs the classic dual-aperture combat configuration — a large ring for speed, a small aperture for precision — with third-generation refinements throughout. The strengthened housing resists crush and impact, the slimmed profile stays out of the way of optics and hands, and the constant-tension spring snaps the sight up crisply from either side of the rifle.
Windage adjusts without tools via positive, tactile clicks, so zeroing a set of MBUS 3s takes minutes rather than a session. For optics-driven rifles that still deserve dependable irons — which is to say, all of them — the MBUS 3 remains the definitive value in backup sights.
Fits 1913 Picatinny top rails on AR-15/M4 pattern rifles, mounted at the rear of the receiver rail. You need clear rail behind your optic, so check the space your mount leaves. Pair it with the MBUS 3 Front (MAG1166) for a complete matched backup system, and zero the pair together.
| Platform | AR-15 / M4 |
|---|---|
| Type | Dual-aperture flip-up rear sight |
| Material | Reinforced polymer |
| Finish | Black, Flat Dark Earth, Olive Drab Green |
| Mount interface | 1913 Picatinny top rail |
| Adjustment | Tool-less windage |
| Brand | Magpul Industries |
| MPN | MAG1167-BLK · MAG1167-FDE · MAG1167-ODG |
Complete your backup system. Order the MBUS 3 Rear today — imported from the USA with all duties paid by us and dispatched tracked from the UK in 7–10 business days, with nothing to pay on delivery.
Explore more: Iron Sights & Backup Sights, AR-15 Parts or browse all Magpul.
| Platform | AR-15 / M4 |
|---|---|
| Type | Dual-aperture flip-up rear sight |
| Material | Reinforced polymer |
| Finish | Black, Flat Dark Earth, Olive Drab Green |
| Mount interface | 1913 Picatinny top rail |
| Adjustment | Tool-less windage |
| Brand | Magpul Industries |
| MPN | MAG1167-BLK · MAG1167-FDE · MAG1167-ODG |
| Category | Iron Sights |
| Shipping weight | 0.3 kg |
| Barcode | 840815132196 |
£5 tracked UK delivery on every order via Royal Mail Tracked 24. Our products are ordered in from the manufacturer rather than held in UK stock, so please allow 7 to 10 business days (Monday to Friday, excluding bank holidays) from the date of your order for it to reach you. Tracking details are emailed on dispatch. UK delivery only.
You have 30 days from receiving your order to cancel it for any reason, then 14 days to send it back unused and in its original packaging. Faulty, damaged or incorrect items are replaced or refunded and we cover reasonable return postage. Refunds go back to your original payment method within 14 days of receiving the return.
It mounts on a 1913 Picatinny top rail on AR-15/M4 pattern rifles, at the rear of the receiver rail. It is intended to pair with the <a href="/products/magpul-mbus-3-sight-front-mag1166">MBUS 3 Front (MAG1166)</a>. You need clear rail behind your optic, so check the space your mount leaves.
The dual-aperture design gives a larger opening for fast close-range shooting and a smaller one for a tighter sight picture further out. You flip between them as needed. If you use irons as more than a last resort, that flexibility is the main reason to pick this over a single-aperture sight.
Windage is tool-less, so you can zero it at the range by hand without carrying a sight tool. The body is reinforced polymer, which keeps weight down and allows the colour range. Elevation is normally set at the front sight, so plan to zero the pair as a set.
It comes in Black, Flat Dark Earth and Olive Drab Green, so you can match a coloured stock or handguard. The steel MBUS Pro rear is the tougher, black-only alternative, and the trade-off is weight and price positioning rather than function. The original MBUS rear is the earlier polymer generation. Our <a href="/blogs/buying-guides/magpul-mbus-3-vs-mbus-pro">MBUS 3 vs MBUS Pro guide</a> sets the two side by side.
This sight is sent from the United Kingdom with £5 tracked UK delivery in 7–10 business days and tracking is emailed to you at dispatch. If it does not suit your optic height or rail, see our returns policy or <a href="/pages/contact">contact us</a> and we'll help sort it.
7 to 10 business days from the date of your order. Every order is sent Royal Mail Tracked for a flat £5 and you receive tracking details by email when it is dispatched.
Yes. We list only genuine parts and optics from the brands shown, ordered in from the manufacturer for your order.
Compatibility notes on this page come from the manufacturer. If you are unsure, email us with your make and model before ordering and we will check rather than guess.
Yes. Bundle & Save applies automatically in your basket: 5% off when you buy 2 items, 10% off at 3 items and 15% off at 4 or more. It works across the whole range, so you can mix and match, and there is no code to enter.
Yes — you have 30 days from delivery to cancel for any reason, as long as the item is unused and in its original packaging. See our returns policy for the details.
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