Some shooters using large-caliber, bipod-supported rifles have reported needing to periodically retighten KeyMod mounts holding bipods on their guns. Nevertheless, beware when loosening the screws-some nuts are not captive and once off, will bounce and roll to the farthest extent possible under distant furniture. The small nuts on the backside of each rail section have enough adjustment to account for different handguard thicknesses. I have not had occasion to try every combination, but so far, so good on compatibility. Theoretically, one company’s KeyMod-based accessories should fit on another’s fore-ends. The beauty of the KeyMod design is it standardizes rail-section attachment. One significant advantage to the KeyMod is accessories can mount directly to the rail, reducing complexity of installation. Overall, this style of attachment works well, and if every manufacturer used the same hole pattern and screw size, I would end my overview here.
![keymod accessories on mlok keymod accessories on mlok](https://cdn11.bigcommerce.com/s-n5c49di9x8/product_images/uploaded_images/m-lok-vs-keymod-min.jpg)
The best bolt-on rails have shear lugs that index in slots milled into the handguard to provide additional strength when items are mounted on heavy-recoiling rifles. 4 attaching screws shear when heavy accessories are attached to hard-recoiling guns. Using too much will cause the epoxy to seep in between the rail section and the fore-end, pulling the finish off should you remove the rail later. If your fore-end has a custom finish, go easy on the thread-locking compound. I recommend using a thread-locking compound for any rail sections you do not intend or want to move around. One weakness with both screw-on and backer-plate systems is screws can vibrate loose over time. Take care that the steel screws do not cross-thread or strip the softer aluminum. While premium fore-ends often have threaded steel inserts, most threaded holes are simply extruded aluminum. The end result of any good mounting system is solid attachment of an accessory to the rifle, but screw-on systems take a lot of the work out of getting to that point. While that worked, modern incarnations are much easier to work with. One brand used to come with popsicle sticks and double-sided tape to help place backer nuts inside the fore-end. Once the tube is on the gun, you have to get the backer-plate (or nuts) inside-working around the barrel-and the further into the fore-end you need to go, the harder it is to secure everything.
#Keymod accessories on mlok install#
They are easiest to install when a handguard is not attached to the rifle.
![keymod accessories on mlok keymod accessories on mlok](https://ar3tactical.com/wp-content/uploads/2021/05/12070-3a374e.jpg)
Once secured, backer-plate rails and accessories are solid. Design variations range from simple-to-attach to maddeningly difficult to get even a single screw in place. Some use slide nuts that ride in tracks inside a fore-end, making installation a snap.
![keymod accessories on mlok keymod accessories on mlok](https://www.totalwartactical.com/wp-content/uploads/2019/11/TR-Handguard-Rubber-Panel-Black-01.jpg)
The modern versions of these rail sections typically attach via backer plates with multiple threaded holes in place of individual nuts. Backer-plate systems that utilize slide nuts on a track make for easier attachment than previous generations, which required the user to remove the fore-end to attach rail sections.