The Volunteer Enterprises Commando Mark III is a closed bolt Semi-auto Rifle chambered in .45ACP and has a Magazine Capacity of 5/15/30/90
The Mark III uses Grease Gun magazines .
Volunteer Enterprises, Inc. offered a 1 year warranty. The Commando line was sold between 1969 and 1977 and in a few other years under different names from various manufacturers .
Grease gun magazines
There were a great many manufacturers of grease gun magazines back when the US army used them, and because of this many of them aren't built to the exact same dimensions.Many grease gun magazines will lock into the Commando just fine but when you try to let the bolt close it just slams the nose of the cartridge into the feed ramp and jams instead of loading it into the chamber.
This is because the feed lips
on some magazines are too close together at the front which keeps
the cartridge captured in the magazine. This is
common with pistol magazines too but they're usually easily fixed by
just bending the lips with a pair of pliars, the lips on a grease gun
magazine are a great deal thicker than the lips on your standard
pistol magazine and can't be adjusted with pliars. So to make the
magazine function some of the feed lips need to be filed away at the
front like in the pictures below.
Obviously you only need to do this if you have a magazine that refuses to allow you to chamber a round, when I first got my Commando none of my 4 magazines would allow me to chamber any brand of ammo until I filed the lips, since adjusting the magazines it's never jammed. If your gun already functions correctly then nothing needs to be done to your magazines(though I've had to modify every single magazine I own)
Here is a good look at the feed lips on my new
magazine, on the left side I have performed the modification to the
feed lip, on the right side I have left it original so you can see what
exactly needs to be removed for the magazines to function.
Obviously this must be done to both lips for the magazine to function properly.