The most prominent feature of the Burton LMR is the twin 20-round box magazines positioned 30° left and right from the rifle's line of sight.

Squeezing the trigger causes the sear to be locked in place, allowing the bolt to return for fully-automatic fire.

It features an open bolt with a blowback to cycle new rounds and eject spent casings downward.

[7] The Burton LMR meets the majority of requirements needed to be classified as an assault rifle; it is select-fire, magazine fed, chambered in an intermediate cartridge, and can be shoulder-fired.

[3][7] The .345 Winchester Self-Loading is a rimless, centerfire cartridge created in 1917 by Frank Burton for the light machine rifle.