There’s very little that has truly been new in the way of firearms mechanisms in the past century. Materials and ammunition design have improved steadily, but the great bulk of firearms mechanisms in use today were designed in the early part of the 20th Century or before. However, there are exceptions, and one truly innovative piece of small arms mechanical technology of the past 30 years is the balanced action concept. This concept exploits the fact that, for automatic weapons chambered in small caliber rifle rounds like the 5.45x39mm, the greatest contributor to the disruption of the weapon after each shot isn’t the rearward force generated by the round itself, but the recoil of the moving parts group, especially as it bottoms out against the rear of the weapon’s receiver. Larry Vickers, on his recent trip to Moscow, got the once-in-a-lifetime chance to fire Kalashnikov Concern’s entry into the balanced-action game, the AK-107 alongside famous Russian 3-gun champion Andrey Kirisenko:
The AK-107 is not the first rifle to use the balanced action, however. We ran an article back in August on the AEK-971, designed at Degtyarev Kovrov, which eventually evolved into the A545, the prime competitor to the AK-12 to be the next Russian service rifle. The AK-107 and AEK-971/A545 have slight architectural differences, but mechanically operate the same way. Even the balanced action AEK-971 itself is not without its precedents. As the inimitable Maxim Popenker explains in this article for All4Shooters.com, inventors were playing around with mechanisms that, while not identical or as refined, sought to do essentially the same thing: Eliminate the rearward impulse caused by the moving parts group.