Too bad they go in for that kind of law enforcement. He may have a good case, not on the violation, but on how they handled it, especially if he called them. But he will NOT get the carbine back; that is guaranteed. Even if someone charged with possessing contraband is let off or acquitted, the contraband is destroyed, since returning it would itself be illegal. (Think being found with 200 kilos of heroin; even if you convince the cops or a court that you thought it was grass seed, they won't give it back to you to sell.)
Are you sure about the carbine having come from CMP? Frankly, the story sounds a bit thin, and it seems odd that they wouldn't check the receiver marking. BTW, you can't "rebrand" an M2 as an M1. If it was ever an M2, even if it was marked that after manufacture, it becomes a machinegun forever, whether it has any FA parts or not.
Jim
Are you sure about the carbine having come from CMP? Frankly, the story sounds a bit thin, and it seems odd that they wouldn't check the receiver marking. BTW, you can't "rebrand" an M2 as an M1. If it was ever an M2, even if it was marked that after manufacture, it becomes a machinegun forever, whether it has any FA parts or not.
Jim