New to me 10 1/2" SBH?

[blaser.306]

The Ruger SBH that I just recently purchased received it's first pre season cleaning and inspection today. From the S/N it was built in the early to mid 80's. While I have only fired a few trial rounds thru it prior to purchase, and with my handloads it does shoot straight. I want to ring the most out of it at 200 meters! After giving the cylinder a thourough cleaning I used pin guages and checked the throats ( that look like they were punched with a drill press) 3 throats ( side by each ) measure .431" and the other 3 measure .432" What would be the sugestion to help this situation along the path to true accuracy? Have the throats all reamed .433" or just open the .431" to the .432" and polish them all up! I do not think that polishing the .432" will remove the tool marks , but may make the Boolits exit a little smoother. Any sugestions or thoughts are appreciated

[kweidner]

I personally would open them to .4325. Take your time. Use 600 grit or finer. Doesn't take very long. Glad you got pin gauges. They really make the difference in accurate measuring.

[NSB]

If it were me, I'd mark the cylinder so I knew which chamber was which, and then shoot it for groups a couple of times. See if it does make any difference. It might, and it might not. I once sent a cylinder back to Ruger and they replaced it for that problem and I've seen other guns that shot well with a difference. I think there's a bit more to it than just the diameter. I think concentricity, spacing, etc add something to the pot.

[NSP64]

I would slug the barrel first. If barrel is tight at .429 than it wont matter. Also check for a constriction where the barrel and frame screw together.