Reaming .45 colt cylinder

[bull]

I have a Ruger BH in .45 Colt that has the typical undersized cylinder throats. I want to get these opened up to try for the best accuracy out of my cast bullet loads. I do have access to a machinist with a mill, not a gunsmith. Is it just a matter of reaming each throat out to .452, or is there a special set up as far as lining up with the forcing cone or something else? I noticed in Brownells a special jig for doing this, isit necessary?  I don't want to screw this up. But I don't have any good gunsmiths around that do this work, (that I know of).

[Camp Cook]

I had the same problem with my 45 Colt s/s Ruger Bisley Vaquero's.....
I purchased from Brownells the .4525 reamer and the bushing kit.
I removed the cylinders from the guns, just holding the cylinder in a rag and with some cutting oil reamed my cylinders out.......
I used Breakclean to wash the cuttings out of the chamber holes before I removed the reamer.
Took about 10 to 15 minutes tops for each cylinder.......
Very easy to do this, so you should have no problem with your machinist friend.
The correct reamer size is .4525 though......
Cam

[gunnut69]

The throats must be aligned with the chambers.  The setup from brownells uses bushings to accomplish that.  Your machinist friend may use a different method(there are several) but dimensions do matter.  The idea is to minimize the changes in diameter the bullet must under go as it passes from the cylinder throat to the barrel throat and into the bore.