Darn good question! I have been trying to figure that out for years. They seem to be rifles that are secondary quality but specifically made in their own serial number range for some use (rather than just something that does not quite pass military inspection). Everyone I have spoken to seems to come down against them being police rifles. There don't seem to be any specifically marked police rifles or pistols for that matter and any property markings found on the concentric circle rifles seem to indicate training or a school.

So, I can't answer your question but I would certainly like to know the answer.

"You can't please everyone, so you've got to please yourself." Ricky Nelson