After days of heavy use on an M4 carbine in both a carbine course and an Israeli Advanced Tactics course, I have to say I was totally wrong. I was astounded at the way the carbine stayed on target regardless of how fast I shot when the GL-SHOCK stock was installed. The weapon seems to recoil straight back into the shoulder with little or no muzzle movement. The first day of the carbine course I used a standard GLR-16 buttstock - one of my favorite stocks. On the second day, I switched to the GL-SHOCK, and that's when my shooting speed increased.

The new GL-SHOCK recoil-reducing stock is a streamlined collapsible stock for M4s and AR-15 carbines. The adjustment latch melts into the shape of the stock with no corners to catch on gear. An auto-tensioning system allows the stock to fit tightly on both mil-spec and commercial receiver extensions. The shape of the stock gives a good, comfortable cheek-weld but is still narrow enough to be effective in tight quarters. The buttpad is rubber with an aggressive tire-tread-inspired pattern for a no-slip grip on body armor. A button in the toe of the stock releases the buttpad to slide down, revealing a waterproof storage compartment. Slings may be attached at several locations on each side of the stock, including at the toe of the stock, at the middle of the rear portion of the stock, around the top of the stock, or with a quick-detach swivel high on either side of the stock. The GL-SHOCK does not have a forward single-point attachment like the GLR-16. For single point attachment, either the points at the rear of the stock may be used, or an MD-SA1 endplate may be installed.

The optional cheekpiece adjusts with twin finger-adjustable locking screws, and is very sturdy, even when fully raised.

The GL-SHOCK Recoil-Reducing Collapsible Buttstock can be installed on any weapon system that uses, or can be adapted to use, a standard M4 Carbine/AR-15 collapsible buttstock. It fits both MIL-SPEC and commercial buffer tubes.

GL-Shock for M4 Carbines and AR-15s

These weapons, chambered in 5.56 mm or  .223 Remington, exhibit pretty mild recoil. I am so used to shooting this weapon system that I really don't notice the push of the recoil, only the amount that the sights move off of the target. As a result, I wasn't really conscious enough of the difference in recoil between the GL-SHOCK and the standard stock to make an accurate report, since I was generally thinking about a lot of other stuff at the time. What I did notice was that the sights moved less when I fired. This is a huge advantage. The recoil-compensation is also an advantage when teaching smaller children or recoil-sensitive adults to shoot.

The rubber recoil pad grips body armor and tactical vests to prevent the butt of the weapon from sliding around on the shooter's chest.

The optional cheek piece is generally not necessary on any flat-top AR-15, since it is difficult to mount optics too high. If only a bit of height is needed, it will work well with the stock extended, but would be in the way of the charging handle if the stock is collapsed. The cheek piece is great for shooters with an optic mounted on top of a carry handle. It will give a proper cheek weld even with the high optic and is then raised high enough that the charging handle goes under it when the stock is collapsed.