I've used Gibbz Arms hex shaped handguards on all three of my AR15 builds, below is a pick of the 20 inch precision rifle. The reason I use the Gibbz handguards is because of the design of the handguard mount, it allow you to clamp the mount in a vise to torque the internal castle nut and tighten the barrel to the receiver without putting any torque on the receiver. Below is a pick of the 20 inch rifle and if you look closely you'll notice it's a side charging AR15.