Ruger Blackhawk 45 Colt cylinder reaming question

[Jcduff936]

I recently purchased a Ruger Blackhawk 45 Colt. I tried loading Jacketed bullets because that's what I had for my rifle and muzzleloader. Everything was fine except the accuracy. I tried different powders and loads. Same thing. Shoots OK at 15 yards but sprays at 25+. I did some research and read about the cylinder issue so I measured mine at .449" and then checked the muzzle and found it to be .450" (checking was done with calipers). I ordered some cast boolits and started trying more loads. There was an improvement but not much. Now I have a complete casting setup and would really like to get this thing to perform. I know that the cylinders are my biggest problem and plan on sending it out to be reamed. My question is how much since the barrel is also undersized. I would really prefer for the gun to shoot cast and Jacketed equally well. Thanks for any help.

[Char-Gar]

A 45 Colt cylinder with throats that run .4525 - .4530 will do well with either cast or jacketed in your handgun. Just size the bullets as close to cylinder throat without going over those numbers and all will be good.

[Outpost75]

I had DougGuy ream both of my .45 Ruger cylinders, .45 ACP and .45 Colt to .4525" and accuracy is stellar, even out to 100 yards. I also had Doug hone my Lee sizer die, as I found out that both of my Lee sizers marked ".452" were actually snug on a .4515" gage pin. I had him hone the die so that a .4520" pin would slide through with a film of light oil, but a .4525" would not enter.

You must also be aware that if you use ternary alloys with a mix of Pb-Sb-Sn, such as wheelweights or backstop scrap, that depending upon the amount of sizing necessary, as the strain induced by the plastic deformation in sizing is relieved gradually through recrystalization, that the bullet will "grow," a few 0.0001ths and that this process continues over time as the bullet age hardens.

Therefore, it is necessary that bullets be sized about 0.0005" to 0.0010" LESS than the cylinder throats to ensure proper fit.

This effect is less apparent with binary Pb-Sn alloys such as Roto Metals 1:30, which I use for my hunting loads. The softer 8-10 BHN bullets are preferable for revolver bullets used in subsonic, non-magnum loads, or as fast as you can drive plainbased bullets accurately in black powder rifles like the .44-40 or .45-70, about 1350 fps.

[Jcduff936]

Thanks for the responses. I saw some stuff regarding DougGuy and was going to ask whether to use him or someone that I had found on Facebook. Just realized that they are one and the same! Easy decision. But I think he's going to be out for a bit so I'll continue waiting. Does anyone know if he laps the barrel as well? Might as well get any and all issues addressed while I'm at it.

[Outpost75]

The interior finish on Ruger barrels is good enough that they don't need lapping, but occasionally you will have a revolver in which the barrel was over-tightened, collapsing it a bit at the root of the thread, which causes a slight choke. If this is more than about 0.001" you will want to lap it out, but less than that usually does no harm.

Fire-lapping works if the constriction is only slight, but if more than 0.001" a turned brass mandrel charged with AA Clover is more precise and just cuts where you need it to. A job for a gunsmith unless you have done it before.

[paul h]

The proper way to measure your barrel is to slug it. When you use the inside arms of a caliber to measure the diameter of a whole it will read undersize due to the width of the face of the inside arms, and this error increases with smaller diameter holes. I would venture to say if you slug your bore and you don't have significant barrel choke your bullets will measure 0.451".

I'd also venture to say if you have your cylinder honed to 0.4525" and again you don't have significant barrel choke your Blackhawk should be capable of very good to excellent accuracy with cast or jacketed bullets.