I was in your same position a little over 2 years ago, I bought everything and tried many things. One thing I quickly learned is we'll probably always do a better job than sending it to a custom shop. I own 3 benchrest rifles with Kelbly's Stolle Panda actions. All of them are supposedly identical, meaning a barrel installed on 1 will fit the other 2. When I bought them they all came with extra barrels that had seen a lot of rounds. All these barrels were matched to that action. I've had 6 or 7 other barrels made that were from information kept with gunsmiths that originally barreled the action. I bought 2 6mm 1:8 barrels on an online forum from a well known smith in PA. I was going to change from 6PPC to 6BR and needed the bolt diameter opened up, so they would handle both cases. Smith said no problem and will not need actions as all Pandas are identically machined. Both bolts were prestine and wanted to make sure the bolt faces were not touched so as not to screw with headspace problems. Again no problem. 6 months later when I got bolts and barrels back, one bolt face had been deepened .004", 1 barrel would screw on 1 action and not the other, 1 barrel wouldn't screw on either. Sent barrel back and it came back and fit loosely on either. Poured chamber casts and both chambers were crooked. The barrels were functional and headspaced with gauges within tolerance, so I shot them and they didn't shoot terrible. But it made me buy a lathe and mill. Then I set about measuring all of those different barrels and they were all over the map. Kelbly's provides a schematic on exact tolerance on threading and chambering and only 1 barrel actually matched those specs. A couple had cone angles off a few degrees, bolt nose clearances that basically had the case head unsupported and at risk of case failure. Gunsmith in business to turn out work can't take 4 hours to indicate a barrel in to < .0002" of runout. I think some do but it depends on who they are selling to and whether your a known shooter or not. Regular ole guy buying a barrel won't know any better. You won't either until you build the tools to measure them. I use a grizzly rod to dial in close initially then use an Interapid 312B-15 DTI to indicate directly on the lands and dial in to where I see virtually identical land to land. Usually dialing in a 3" or so area that is running exactly true to the spindle. This means the muzzle ends up where it ends up. Some of these barrels have horrible runout on the muzzle end when the chamber is running true. Most of these are Kreiger barrels, couple Shilens, 1 Bartlein. A couple barrels have virtually 0 runout on both ends. The point is, smiths like Alex Wheeler would not have even used those barrels with runout like that, he would have sent them back and exchanged them. Where do those end up? Sold online by someone else. I think it was in Tony Boyer's book where he talks about buying barrels by the dozens. They are chambered and tested, if they don't shoot great from the start, they are sold.
So doing it yourself, you can take the time and get them dialed in to the best of your abilities and you'll learn much in the process. That still doesn't mean they'll all be hummers. In the end, the target is only thing that matters.
