SDC
Member
I have my doubts that they'd use a PROJECTILE firing "gun" for any sort of propulsion, when they could get safer, more consistent propulsion by using some sort of compressed gas; in this pic, Gemini astronaut Ed White is carrying a compressed gas "gun" for propulsion during a spacewalk.
http://www.scienceandsociety.co.uk/results.asp?image=10300399&wwwflag=2&imagepos=4
http://www.scienceandsociety.co.uk/results.asp?image=10300399&wwwflag=2&imagepos=4