Thanks to people wanting to wave around broken science in a dick measuring contest, high tech weapons are now based on a trust system. That is, if we trust you enough to make it, you can have it. In addition, if a weapon is deemed to be OP, or over powered, it is denied. It doesn't matter if it exists in real life or not.
The grip and trigger disconnect from the whole launch tube, revealing a modified pistol that fires .50 caliber bullets. Holds up to 10 rounds per magazine, but Lunae only carries the one always inside the pistol.