Some of the more notable weapon designs that used this concept were the FN/FAL and M14 rifles, which used a full sized rifle round in both the semi-automatic and fully automatic mode. One of the most unique aspects of this weapon was that it fired from a "closed bolt" when shooting in the semi-automatic mode and an "open bolt" in the fully automatic mode, which aided in reducing cook-offs.
As a “light machine gun” its utility was greatly limited by the 20-round magazine limit and the light weight barrel. It had no provision for belt feed and the constant magazine changes would have prevented building a solid base of cover fire. On top of that the heavy-weight 8mm Mauser cartridges would have precluded carrying large amounts of ammo. Users carried 20 magazines in a special harness-like strip, meaning each user had 400 rounds which would last a light machine gun in fire suppression mode only about three minutes.
It was accurate, light (10 pounds), sleek, had extraordinary pointability. However, “because physics, in the end, can’t be defied, kicked like the mother of all mules”.
The top of the receiver of these rifles were specifically machined with a long dovetail type base designed to accept the two scope rings. The rings each have a single locking lever that allowed easy installation and removal of the scope depending on the specific combat scenario; general combat or in a limited sniping role.
These rifles were developed fairly late in WWII and were specifically issued to only German Paratroopers. It is estimated that only appropriately 5000 were ever manufactured with most being destroyed after the war with only a few surviving intact examples in collectors hands today.