Apologies for the bump, but I feel this needs to be said so people don't get the wrong impression from Couzin's post.
Couzin, weapon manufacturer's fire weapons after production, and many don't clean them. Sometimes there are issues with quality control at factories of all kinds. I've dealt with the guys at AJC quite a bit, I used to live in that area. I've bought every gun I own from them, bought used and new guns, and I've never had a problem that they couldn't help me solved. I've sat in the shop, just browsing (I find it likely that many of you find this enjoyable as well) and I've seen people come in and have similar issues. And I don't believe that Alan would sell as used gun as "new". I think that a lot of people just don't realize that even a "new" gun has been fired at the factory.
As much business as he does, I don't think he'd need to use cheap tricks like that.