the barrel is one issue, the guy chambering the barrel has a LOT to do with how that barrel will shoot...MOST forget this.
I have three X caliber barrels, groups will make you stand up and shout they are so good!
There are a lot of pipe fitters out there, and as you read these comments, you have no idea how the guys' bench techniques are, cleaning habits, wind reading ability, etc.
About 5 years, I sold my pet 7 mag to a guy. This was a Browning A bolt that shot bug holes, no kidding. I gave him the targets, load data, a dummy round with the OAL. Not much for him to do but duplicate the loads. He called me up and said that the best he could do with the rifle was 1 1/2". I spent quite a few hours going over details with him in loading techniques and he had changed just about every component. Then found out he did not have proper cleaning equipment. But the real kicker was he was laying on the ground shooting off a harris bi pod....7 Mag...
I have X caliber barrels in 6 BRX, 6.5x47 Lapua, and 6 XC, all are shooting bug holes. Now, these 3 barrels are just a sample. None of them copper foul, and all were shooting tiny groups within 12 shots, with no break in. The guy that does the chambering indicates the barrels in through the headstock to the 0.0001. Using this technique, some rather poor quality, cheap barrels have shot extremely well over the years. If a barrel is chambered with .003 run out between the chamber and bore, it may not shoot well at all, or may just be very finicky on how it does shoot. This is the issue you deal with a lot with factory barrels.
I do believe that X caliber is a rising star for several reasons, they have brand new equipment, and the best equipment, including a new Honing machine that some barrel makers do not have. This Honing machine gives consistent dimensions from front to end, and does away with any drill marks from when the barrel was deep hole drilled.
I like the X caliber folks because they are an American Success Story. These people were making barrels for Remington. Remington came up and told them that they were moving the company to Alabama and offered them jobs. They did not want to move to Alabama. So, they found an investor with deep pockets, who bought them all new equipment, latest and greatest. They have been keeping their prices way down so as to get well known in the market place. They have excellent customer service, and that is an understatement. I like pulling for the underdog, especially when they are trying so hard to put out a quality product, and break their necks serving the public.
When you evaluate any barrel, remember, the gunsmith and his attention to detail can make or break the whole deal. Little details like him having a set of pilots that will allow him to fit the proper pilot for the reamer bushing so the reamer is not flopping around in the chamber cutting an over size(not centered) chamber, checking his set up several times to see if the machining process has caused the barrel to move out of alignment by .0002-.0004, checking to see if the bullet will be getting started in a straight part of the barrel, checking for tight and loose spots in the barrel, etc.
Attention to detail will allow bargin basement barrels to shoot bug holes with regularity, such as ER Shaw, Green Mountain, and Adams and Bennett.
Then when you get a good X caliber, you just have to pinch yourself. I also have Krieger, Brux, Broughton, Shilen, Hart, Krieger, Lilja, and Bartlein.
Using the Hawkeye bore scope, X Caliber barrels compare with all top brand barrel makers, you don't see drill marks, gouges, thin or wide lands, short lands. For this reason, and the experience that I and about half a dozen friends have had with X caliber, I will be buying half a dozen more this year.
I am still not going to give up certain other brands, but when you can save $100 and still shoot groups in the sub 2's an lower, what is not to like? Tiny groups on a hunting rifle are a great thing, especially if you can save some money.