Re: used barrels
Mark has a good point. Buying a used barrel from an unknown source is like buying a pig in a poke...or whatever they say.
The seller may claim to have fired 1,200 rounds but there isn't really any way for you to know. Besides, total round count only tells part of the story when it comes to barrel wear. How hot the tube was shot and how well it was maintained can also be significant factors.
I once sold a Shilen Select Match barrel to a guy on the internet. I keep accurate records of everything I load and knew that the barrel saw just under 1,000 rounds. However, I also knew that he didn't know if I was telling the truth. He asked if he could have 2 days to borescope the barrel with the option to return it for a refund. I had no problem with that and the barrel was shipped.
I guess he was happy because I never heard from him again.
Just my 2 cents on buying used barrels.