|The following is based on Van Buren and has not been confirmed by canon sources.|
There is no mention of any weapon chambered for it both in the tech demo or the design documents.
- Heavy rivet AP
- Heavy rivet HV (high velocity)
- While it doesn't appear in the Van Buren tech demo, it is still present in the game files and can be spawned with the console command CreateEntity AmmoHeavy_Rivet.amo.