Just got an authentic WWII Thompson 30 round magazine...

[Ukas]

Nope, but close... Grease Gun was M3A1.

This is M1928

And this one M1A1

edit: found M3A1 pic too.

M3A1 was indeed cheap, made of plate (if it's the correct term) and very simply too. Slow firing, poor accuracy, but working and I guess that's the most important thing. With a good finger-technique, you could fire single shots with it. I tried this gun too in some wwii collectors shooting happening here in Finland.

 

[Bugfatty300]

I know what an authentic 30 round thompson rifle is, but magizine

A magazine is the box that feeds ammunition to the gun.

 

[nonconformist]

I wasn't aware the grease-gun was a .45, I thought it was .303.