Sizing the 270 SAA For Ruger Bisley

[GSaltzman]

Did some shooting with this bullet and the accuracy was not what I had hoped. Here is what I have found. Slugged the bore and it measures .451. The chamber mouths are mostly .4545 with two that measure .455. I confirmed by pushing a cast boolit that measured .454 through all chambers with little to no preasure. I was shooting boolits sized to .452 and tried loads using Unique, Power Pistol and 296. Over the chrono the loads were very consistant and was pleased with that part of it. Now, with the chamber mouths being so much more bigger than the bore would I be okay shooting boolits sized at .454 or would that be to big for the .451 bore causing higher pressures? Boolits were ww metal and were loaded air cooled and water quenched.

[fredj338]

My RBH has .4505" chamber mouths & .452" bbl. So I am going to open to 0.4515". I get a little leadng w/ that bullet in the first 2" or so of the bbl. They shoot great though cast of 50/50 ww/lead. You might try sizing to 0.453" or shoot as cast (they are close to 0.454") & see if things improve.
Erik made a HP in one cav & they shoot very well.
http://img.photobucket.com/albums/v703/fredj338/452-268-1K.jpg

[HORNET]

Unless you're already pushing pressures to the limit, you should be fine sizing to .454 diameter. It will raise pressures a little, but only a little. You may well get better groups due to better alignment in the chambers, but maybe not. Try it.

[GSaltzman]

Hornet, Not pushing anything to the max. My next step was to try sizing larger or to load unsized boolit. Already have some lubed but it will have to wait. Thanks for the replies.