They are sold everywhere around in Sirius (check in criminals owned bases) and can just be bought by Smugglers (i.e. player need to have equipped Smuggler Role-Play license.) They are highly profitable but transporting them is also very dangerous (understand as illegal = police (NPCs and players playing Police Role-Play) see this as a serious crime. List of all BMGs can be find here.
![](https://swat-portal.com/forum/wcf/images/avatars/43/2720-43bc313e31033fa6c57de8b7b024ec453286d69c.png)