My 243AI barrel is rechambered barrel off of a 12BVSS that was a 243. It now has a fair number of rounds down her, without checking I would say she's nearing 3,000. With that said I am running the 58gr V-Max out of her at just over 4,000fps and that is a conservative load. I keep it there rather than turning it up just because its plenty fast, flat, and accurate. It also lends to even better brass life. I bought this barrel slightly used, and the previous owner was shooting 70gr Blitzkings over RL-17 at 3850fps and claimed that was a bit below what it was capable of for speed.

Accuracy is good, normally giving me .3-.6" range groups at 100yds. I am sure in her prime she did much better. I have a buddy with a 243AI McGowan that shoots .4" all day long and another buddy that has a CBI that does just as well.