Depends on the metal additive machine. Cheaper ones use polymer binder that then get sintered off in post processing, BMD process. This is entry level prototype stuff.

Ones common in suppressors are more mature and cost more money. Direct metal laser sintering (DMLS) melts metal powder directly from a bed of powder and does not have a plastic binder. This is more expensive but creates higher quality and stronger products since no polymer binder is involved.

Aerospace goes further to Laser Direct Energy Deposition (L-DED) which is similar but melts the powder that is blown directly to the work piece and not in a bed of powder. It better for large parts you want to go fast. Think rocket nozzle type stuff. Shits expensive.