It's too bad that the Quality of some of the barrels is like this, but it's the way it is, No 2 ML's (the same brand) are exactly the same or shoot the same, that's just the way it is. So when you find a (SWEET) Shootin Gun/ML KEEP IT!
Some JB's ought to take care of it, but like other's said shoot it a bunch of times and it should smooth it out. If not and your Not Happy send it back and get another Barrel or have them rapair it, or ask for a New One.
Best of Luck to You.
(BP)