My LGS has a few used 5.56 cans for between $250 and $300. They have Gemtechs and another brand, I don't recall. All are direct thread and were trade ins from the SWAT teams of a midsize city (Temple, TX) so high round counts. They came mounted to 10.5 Colts but are being sold separately. The rifles are for sale as well and have seem some hard use. Some of the cans look to be in good shape while others display what appears to be degradation of the baffle holes. It looks like erosion but could be baffle strikes. Given the automatic $200 additional cost and long wait I can't see going cheap for such a purchase but was curious if any others had thoughts on the matter. I have read though that cans actually can get quieter with time because of all the carbon deposits but it seems the baffle hole erosion would offset sound dampening from carbon.