Ruger SP101 .32 H&R

[trooperdan]

I getting ready to load for my SP101, cast some boolits up, sized to .312 but when I checked the mouth of the cylinders looks like they are about .309! Is this usual in this model and won't it cause a lack of accuracy?

Should I size down to .310 or so or see about having the cylinder honed out about .0003?

[MT Gianni]

What does the bbl slug? The cylinder will size them down for you from .312 to .309 with out major pressure problems but if your bbl is larger then accuracy will suffer.

[Dale53]

My Ruger SP101 has .312" cylinder throats. I learned that I can size the bullets to .313" and they would shoot with accuracy. I have several other .32's that can use .314" bullets but respond well to .313" bullets. That allows me to shoot .313" in all guns so, now, that is my standard.

Only tests will show you. However, .309" cylinder throats in any of MY guns would see a reamer as I guarantee you that your barrel groove diameter is larger and I would EXPECT to see leading, and lots of it.

FWIW
Dale53

[NoZombies]

...That allows me to shoot .313" in all guns so, now, that is my standard...

I have gotten lazy with my .32's, and I size everything to .313. They all shoot just fine that way. But then, none of my .32's have .309 throats.