I have a Standard Products carbine with no manufacturer's markings on the barrel. The finish on the barrel matches the rest of the rifle, and it has the P marking. It's definitely a military configuration barrel, not aftermarket or commercial. The carbine still has a type 2 band on it, and there are no type 3 band marks on the barrel.

Rifle looks all proper and correct for a typical arsenal refurbished/upgraded carbine.

Anybody ever seen anything like this before or have any information on it?