What is this, came from some friends clearing out their garage

[GGD]

Some more info at this site. Looks like pointy end on that one wasn't the best design and was replaced with a better one with a blunt end.

http://www.designation-systems.net/dusrm...ocket.html

The M6 and M6A1 rockets had a pointed nose, which led to deflection from the target at low impact angles. Therefore a new M6A3 rocket was designed with a much more blunt nose. The M6A3 also had a new circular fin assembly to improve flight stability. The launcher for the M6A3 was designated M9A1. The 2.36-Inch Practice Rocket M7 was an inert training rocket for the Bazooka.

Lets hope that you have a M7 instead of an M6.