M1 Grenade adaptor, Mk. 2 grenade, and M7 grenade launcher
M1 Grenade adaptor, Mk. 2 grenade, and M7 grenade launcher
The M1 adaptor was a device meant to turn a standard hand thrown Mk. 2 fragmentation grenade into a rifle grenade.
The grenade was seated into the cup of the adaptor, held in place by metal fingers. The spoon of the grenade was slotted inside of a retaining clip.
To fire, the entire assembly would slip onto an M1 Garand that had been fitted with an M7 grenade launcher. The M7 provided a surface for the M1 adaptor to sit and it cut off the gas system in the Garand. The pin on the Mk. 2 grenade would be pulled, and the rifle would fire a hand loaded blank cartridge.
Upon firing, the retaining clip in the M1 adaptor would move backwards, striking a specially designed brittle metal retaining bar which would break. The clip would fall away entirely, allowing the spoon of the Mk. 2 grenade to release. The grenade would detonate with its normal timed function.
The M7 grenade launcher was replaced by the M76 grenade launcher when the U.S. military adopted M14 rifles. The M76 provided the same ability to launch rifle grenades.
Rifle grenades were eventually replaced by 40x46mm dedicated projected grenades for standard applications.
so it's propelled just by the force of a special blank cartridge, am i reading that right?
Yes. The blank cartridge is loaded with more powder, and this has more power than a standard cartridge.( I can’t find specific numbers at the moment but will look later.)
The power of the propellant pushes the rifle grenade assembly off of the launcher. You can see that the launcher has grooves in it, those show it has obterating bands, or bands of metal that expand under pressure and help create a seal which further increases pressure.
The launcher cutting off the gas system of the Garand means that no gas (which means no power) is wasted to needlessly cycle the rifle, and it protects the rifle parts from the high pressure.
Your question and unfamiliarity with rifle grenades does make me want to post other examples of rifle grenades that are a bit less complexly assembled.
Yes