The Super Modular Rail (SMR) MK4 is Geissele’s ultra-rugged M-LOK option. This is Bill's OG SMR !! These rails are purpose-built and feature integrated M1913 Picatinny rail sections at the fore of the rail in the 3, 6 and 9 o’clock positions. Maximum venting for heat dissipation also dramatically reduces the rail's overall weight, while maintaining its same strong and rigid platform. Utilizing Magpul's M-LOK technology at the 3, 6, and 9 o'clock positions, as well as the upper 45 quadrants. The SMR MK4 is both versatile and modular, allowing the user to tailor their platform to his or her unique needs.
The SMR MK4 also features Geissele's proprietary 2.25" long barrel nut. This increases the surface contact where the rail interfaces with the receiver and creates a platform that can be trusted to be straight and true the entire length of the free float rail. This increases accuracy and zero repeatability during disassembly and reassembly when performing maintenance.
We get a lot of questions about the length of the rail, usually, along the lines of, "Hey Charlie, what rail length should I get?" Well, at 13-1/2" you are not going to run an 11-1/2" barrel normally, unless you doing something to trick-out a suppressor under the rail... Hmm. So, most people are looking at 14.5" to 20" barrel, running mid-length or rifle-length gas system. If you are unsure which Geissele rail to get, it is hard to go wrong with the Mk4. Get 'er done!
btw, why after all these years, and typing Bill's last name at least 2,000 times, do I still find Spell-Check telling me I fucked up again? Meh...
Oh, we also sell this is DDC, or FDE, or Taupe, or Sand, and if you are looking for that color, check out the Mk4 3.5" DDC rail here
| HEIGHT: | 2.4" |
| COLOR: | Black |
| MATERIAL: | 6000 Series Aluminum |
| FINISH: | Type 3 Hardcoat Anodized |
| LENGTH: | 13.5" |
| INNER DIAMETER: | 1.35" |
| OUTER DIAMETER (DAQ*): | 2.11" |
| WEIGHT: | 11.8oz (13.5oz w/ barrel nut) |
| MPN | 05-278B |
*DAQ - Distance Across Quadrants
