What’s the mechanical accuracy of these grenade launchers? And what kind of overall accuracy can a skilled shooter expect versus a semi-trained shooter? Are “groups” on the order of 10 yards at 100 yards?
And what’s the lethal radius versus the injury radius of the standard grenade in typical terrain?
It turns out that grenade-launchers are plenty accurate:
Those are good questions. Because of the high trajectory, you’re limited to 100-200m against a point target. (Like shooting through a window, one of the ranges we used to use had a window at 175m and I could put a round through that pretty consistently). Anybody who’d fired a few rounds and used the sight properly could hit a window at 100m. Area target like troops in the open you could hit with plunging fire to about 300-350m. At that point you’re at high angle (in the artillery definition) and going any higher brings the round back towards you.
The old M79 had a ladder sight and a close in battlesight (60m) when you flip the sight down, but it was calibrated for 1960s ammunition. If you used that battlesight with 1980s or newer rounds, the round’s impact was more like 30 than 60m and you could (and I did) hit yourself with shrapnel from the round. At that range it was not very lethal — it only penetrated about 1/32? — but it was still hot enough to burn your skin.
The Army claims the following for all 40x46mm antipersonnel grenades: kill radius of 5m, and casualty radius of 130m (the latter is greatly exaggerated, in my opinion). During the Vietnam War they claimed a kill radius of 5m and an “incapacitation radius” of 15m for these same rounds like the M381. The M381 went out of service because it was hazardous to fire in forests due to its very short arming distance (as little as 3m). Real problem in Vietnam triple-cap.
So, if a soldier can put a grenade within a meter or two of his target, it sounds like a smaller grenade might be in order.