[There are enough invariant handguns on the Wasp for everyone to have one, and a limited supply of ammo. In theory the matter printer can produce more, but given the printer's known issues, he probably wants to save that for a last resort. If the Nirai station's security is lax, you may not have too much difficulty getting weapons past whatever scanners they have.]

[EDIT: You can have a small firing range, but it won't do anything fancy with moving/pop-up targets &c.]