The BCM A/T Optic Riser is a 0.525" Picatinny riser for AR-15 and M4 rifles, raising any 1913-mounted optic onto a longer, higher rail platform via BCM's angled-torque clamp.
Every one of the five versions rises by the same 0.525" (13.3 mm). What changes between them is footprint: how many recoil slots the riser carries and how far it extends over or forward of the receiver. That rise puts a typical lower-third optic at roughly 2.16" (55 mm) of optical centerline and an absolute-cowitness optic at roughly 1.93" (49 mm) — a head-up posture that is easier to hold, easier to hold consistently, and easier to work under night vision or with eye protection and a helmet.
The A/T in the name is Angled Torque: a patented clamp that applies triangulating force rather than pulling straight sideways, giving approximately twice the clamping force at the same torque as a legacy horizontal interface. Multiple integral recoil lugs engage the receiver rail so the riser cannot creep. The body is aircraft aluminum alloy, hard-coat anodized to Mil-A-8625F, with a nitride-coated steel clamp.
A higher, longer optic platform means a more natural head position and room to lay out a red dot, a magnifier and a backup sight on one continuous plane instead of fighting for space on the receiver rail. The low-profile A/T interface keeps the whole assembly snag-free and leaves the riser stalk usable for bolt-on or QD accessories along its length.
Key Features
- 0.525" (13.3 mm) rise on every version — a consistent, repeatable sightline whichever footprint you choose
- Angled Torque clamp — approximately twice the clamping force at the same torque as a horizontal interface
- Multiple integral recoil lugs — the riser engages the rail and holds zero rather than creeping
- Five footprints — from a 5-slot receiver-top riser to an 18-slot cantilever platform
- Usable stalk — Mil-Std 1913 attachments mount anywhere along the riser, not just on top
Compatibility & Fitment
Fits any Mil-Std 1913 Picatinny receiver rail on an AR-15/M4, and accepts any optic or mount with a 1913 clamp. Choose by footprint, not by height — all five rise by the same 0.525". The 5-slot is a compact riser for a red dot alone; the 11-slot and 13-slot give room for a magnifier, night vision or thermal behind the optic, with the 13-slot covering the full length of the upper receiver. The 10X5 and 13X5 add a 5-slot cantilever section projecting forward of the main body for layering a magnifier ahead of the receiver — the X5 is a rail section, not a different height. Check the riser length against your handguard's top rail so the cantilever has somewhere to sit.
Technical Specifications
Platform | AR-15 / M4 |
Fits | Any Mil-Std 1913 Picatinny receiver rail; optics and mounts with a 1913 clamp |
Type | Optic riser, 0.525" (13.3 mm) rise, A/T angled-torque clamp |
Material | Aircraft aluminum alloy; steel alloy clamp, nitride coated |
Finish | Hard-coat anodized, Mil-A-8625F |
Length | 5-slot approx. 2⅛" (54 mm) · 11-slot approx. 4.5" (114 mm) · 13-slot approx. 5¾" (146 mm) · 10-slot + 5-slot cantilever approx. 6⅛" (156 mm) · 13-slot + 5-slot cantilever approx. 7¼" (184 mm) |
Mount Interface | A/T angled-torque clamp to Mil-Std 1913 Picatinny, with multiple integral recoil lugs |
Brand | Bravo Company USA |
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
Do the five versions have different heights?
No. All five rise by exactly 0.525" (13.3 mm). The number in the part code is the count of recoil slots, which sets how long the riser is and how much rail you get — not how high it sits. An X5 code means a 5-slot cantilever section projecting forward of the main body, again at the same 0.525" rise.
What optic height will I end up at?
Measured at the optical centerline, an optic that normally sits at lower-third cowitness ends up at approximately 2.16" (55 mm), and an absolute-cowitness optic ends up at approximately 1.93" (49 mm). The exact figure depends on the mount you clamp to the riser, so work from your own mount's published height plus 0.525".
Which size should I buy?
For a red dot on its own, the 5-slot is enough. For a red dot with a magnifier behind it, or night vision or thermal in line, take the 11-slot or 13-slot — the 13-slot covers the whole upper receiver. The 10X5 and 13X5 carry a 5-slot cantilever forward of the receiver, which is what you want when the magnifier or a second device needs to sit ahead of the optic.
What does the A/T clamp do differently?
It applies torque at an angle so the clamp force triangulates onto the rail instead of pulling sideways, which BCM states gives approximately twice the clamping force at the same torque as a conventional horizontal interface. Combined with multiple integral recoil lugs, that is what keeps the riser — and therefore your zero — where you put it.
