However, accessories designed specifically for the Picatinny rail system will have notches that are too wide to fit the narrower Weaver spacing. In the civilian market, the Picatinny rail has become the most common rail for AR-15s. 1913 quad rail is the strongest rail by far but you sacrifice some ergos. The easiest way to tell them apart is that the grooves that hold things in place are .206 inches wide on a MIL-STD-1913 (Picatinny) rail and only .180 inches wide on a Weaver rail. I also agree that there is no QD coupling designed for M-LOK. Semedea Picatinny Rail Accessory Set Compatible with Mlok Systems, 3-Slot 5-Slot 7-Slot 13-Slot Aluminum Picatinny Rails Section with 9 T-Nuts & 9 Screws & Allen Wrench 4.6 … 3. For the most part, few people will need to worry about this because if you are buying any tactical rails or accessories they will be Picatinny. The Picatinny rail (top) has wider slots than the Weaver rail (bottom) Simply stated, this difference means an accessory designed for a Weaver rail will fit into the wider Picatinny rail slot. A keymod/mlok specific attachment (vs adding a 1913 rail section) keeps the accessory closer in. Keymod rails feature a 1913 Picatinny rail on the top side and keymod accessory “holes” on each other side. M-LOK, standing for Modular Lock, is a free licensed firearm rail interface system developed and patented by Magpul Industries.. M-LOK allows for direct accessory attachment onto the "negative space" (hollow slot) mounting points, and is a competing standard to VLTOR's open sourced KeyMod system for replacing the ubiquitous Picatinny rail in some applications. With a harris bipod, for example, a mlok/keymod sling swivel stud will be closer to the bore than any mounting option for a quad rail, so you get a lot more stability. I agree that using a short picatinny rail section for quickly attaching/detaching a bipod is a good idea. The military modified the M16A2 and M4 carbine to use Picatinny rails shortly after the introduction of the new rail system. 2. Personally, I have the MAGPUL M-LOK bipod in use on one of my ARs and it stays mounted. But if you want bombproof go with 1913. If you currently have some KeyMod rails continue to use them but buy either Quad or MLOK going forward. A number of mounting spots can vary depending on the manufacturer, but they all tend to have the same sleek and slim design. Whereas the earlier Weaver rail is modified from a low, wide dovetail rail, the Picatinny rail has a more pronounced angular section. Howdy, I’m looking into getting the Magpul bipod, and trying to decide between the rail version or the MLOK. The picatinny accessory rail system has been the standard for bolting stuff to our AR-15s and other rifles for several years now. Modern Day Picatinny. I have an AR with the MLOK handguard, and could either attach a 3 slot rail (the MLOK adapter) and put the bipod on that, or get the MLOK version and attach directly to the handguard. 1. That, however, is not important to everyone. MLOK and KeyMod are identical for ergonomics but MLOK is stronger so go with MLOK. It’s an excellent system, especially for mounting optics, but including picatinny rails on a rifle’s foreend/handguard can add a lot of unwanted bulk and weight. BCM-15-MLOK-Rail with Picatinny on top.