The Stock Taso Barrel had minor visible imperfections in the crown. I didn't expect such a dramatic improvement, but there you are. Remember, this is not a cure all. If there is nothing wrong with the crown on your barrel, re crowning will not help. But I am going to re crown all my barrels anyway.
Tiny imperfections can make big differences in accuracy.
While the Carbine is a very good Gun, I could never get the velocity variations stabilized.