Re: 22-250 re-barrel chamber questions
I have never been able to touch the rifling with bullets that I have the twist to stabilize. That, in and of itself, never really bothered me. I am not one obsessed with loading everything to "jam" length in the rifling. In fact, not one of my rifles has shot better touching the rifling. All of my rifles produce their best accuracy from .030 to .080 off the lands.
I worked up loads using 50g VMAX and 52g AMAX bullets. I also tried 55g Blitzkings and Hornady 60g soft points. Neither of those showed promise. The 50 and 52g bullets did OK and I was eventually able to get them down to around .6 for five shots @ 100 yards and around 2.5" at 300 yards.
The groups are not bad, but I would really like to do better with this rifle and I don't believe that is possible with the current barrel. The gunsmith did a first class job of installing and crowning the barrel. No problems there. I don't know enough about machining to evaluate the reamer used, so I am not sure if that is the cause of the freebore, if the freebore is the problem, or if the amount of freebore is normal for a 22-250.
Bedding is not the problem. The rifle is not stringing vertically or horizontally. Nor is it shooting the "double groups" that are a classic sign of bedding problems. It is shooting nice round groups. They are just not tight enough for me.
Hired Gun, I believe you correctly identified the problem when you mentioned barrel quality. The A & B barrel is obviously not a great barrel, but it suited my purposes when I initially had the rifle put together. It had some problems wth point of impact shifts related to fouling early on. I fire lapped the barrel (using only the three finest grits so as not to move the throat) to deal with that issue and it went away. The barrel has since shot just OK and just doesn't show the potential to do any better.
Personally, I have had very good luck with Shilen barrels and believe them to be quality products. FWIW, I have a 6.5-284 with a Krieger barrel that shoots very well. However, my Shilen barrelled 6.5x55 shoots right with it in the accuracy department.
I believe that the Shilen barrel that I intend to have installed will do a lot better than the A & B did. I feel it is of good enough quality to achieve my accuracy goals. My concern is making sure that enough attention is paid to the machining to ensure that the quality of the barrel does not go to waste.
That is the reason for my concern over chamber dimensions. Not knowing what is considered normal for a 22-250, I really don't know how to evaluate that.
Maybe a call to PT&G would be in order here...