When it comes to choosing a handguard rail, the options can feel overwhelming. Do you want a drop-in or a free float? Do you stick with the standard Picatinny handguard rail, or do you try one of the more modern options? Do you want rails all the way around the barrel or just on top? The joy of the AR 15 is that it can be easily customized to better fit your preferences. The downside, if you can call it one, is that it can be hard to narrow down the decisions if you don’t know where to start. And, because a lot of it boils down to personal preference, you’ll see a variety of different owners/groups giving conflicting advice. The handguard rail is a great way to help your grip, change weight balance, and attach accessories. If you’re not sure where to start, here’s a basic comparison of different free-float rail styles to get you going:
Picatinny Handguard Rail
The Picatinny style is generally considered the standard for AR 15 rail options. It’s made up of raised rails that look similar to railroad ties, and accessories attach by way of the dips between rails. They’re the standard largely because they make it easy to attach accessories quickly, without a lot of hassle. The big downside, however, is that each of those raised rails causes the weight to add up quickly. They can also feel a bit like grabbing a cheese grater, which can impact the firmness of your grip and affect accuracy.
KeyMod Handguard Rail
The KeyMod (KMR) handguard was made as an answer to calls for lighter handguard rail options. This style features keyhole-shaped slots that are designed so you can easily drop in accessories, push forward to the narrow end of the slots, and tighten the nuts to secure. They’re lightweight and make attaching accessories simple — and as an added bonus, the KeyMod system design specifications are all open source, so manufacturers can easily get a hold of the information they need for their own designs. The downside of this is that, since it’s all open source, the KeyMod system doesn’t have much in the way of industrial support. Also, while the KMR handguard rail held up well under most stress tests, it didn’t have a perfect success rate when dropped on the ground. If you know you’re clumsy, you may need to re-attach accessories more frequently.
M-LOK Handguard Rail
The M-LOK rail system emerged around the same time the KeyMod system was coming to the fore. Both systems are similar in many ways, particularly in the focus on lightweight but durable handguard rail options. Unlike the KeyMod rail, however, the M-LOK rail is comprised of long thin slots. The idea is that accessories are attached with their t-shaped nut so accessories can’t just pop off easily. This offers a bit of a bonus and downside simultaneously. The good news is you have more flexibility in attaching accessories; you aren’t restricted as much by the slots. This does, however, make it more difficult to attach your accessories where you want them, and you may find it takes longer to attach just because you’re left fiddling to get the placement right. The good news? US SOCOM performed a range of testing for both M-LOK and KMR handguards and the M-LOK had a 100 percent success rate in accessories staying attached when dropped on the ground. You may be a bit more restricted in which accessories are compatible, since M-LOK plans aren’t open source, but they’ll stay attached!
Best Of All Worlds: Combination Handguard Rails
Still can’t decide? That’s okay. It’s better in the long-run to take your time and find the right option for your preferences. One of the benefits of KeyMod being open-source and M-LOK being willing to share their plans is that there are also hybrid handguard rail options out there. For example, Bootleg, Inc. has handguard rail options that combine Picatinny rails with either KeyMod or M-Lok styles in one handguard. If you already have Picatinny-compatible accessories but you want to branch out and/or lighten your load, check out our proprietary PicMod or PicLok rail systems and enjoy the best of both worlds. Shop both and other custom AR parts with Bootleg, Inc.!