Cylinder throats on .30 Ruger Blackhawk

[zxcvbob]

I have a .30 Blackhawk, and the cylinder throats are so tight I have to seat bullets *very* deep in the cases in order to get the rounds to chamber properly. Almost shove them all the way in like wadcutters. Also, I mostly shot cast bullets, and the leading edge of the throats shave a bit of lead off the bullets and it builds up so that the cases don't seat all the way in.

Surprisingly, the gun is very accurate and it doesn't lead the barrel even when I push cast bullets way beyond anything reasonable.

I've been thinking about buying a 23/64" taper pin reamer and easing the throats just a little by hand, to provide more clearence for the bullets.
http://www.icscuttingtools.com/catalog/page_201.pdf

1. Is this a bad idea? I know if I go too deep with it, I'll remove the step that the cases headspace off. Also if I go too deep, I'll open them up too much and get blowby.
2. I assume a tapered reamer will self-center in the hole.
3. Will a standard reamer even cut the steel in a Ruger cylinder, or would I need to use a cobalt reamer?
4. Should the reamer have enough clearance in the chambers that I can wrap tape around it to keep it from scarring the cylinder wall? They are already pretty rough, but I don't want to make them worse. (this assumes that the answer to #3 is that the reamer is easily hard enough)

Thanks.

 

[machinisttx]

I would obtain a set of gage pins and find out what size the throats are currently. If they're undersize, Ruger will fix it.

Then, if I needed to open the throats a little, I'd have it done on a honing machine. I had to do this on my .45 Colt Blackhawk.

If you're going to use a reamer, cut a case off and slip it over the reamer to guide it through the chamber.

Are you sure the bullets are properly sized?

 

[zxcvbob]

I measured the bullets with a B&S micrometer and they were .309" (just like it said on the box.)

I suppose I could resize them down to .308 (I don't have a die that size, would have to order one); that might be easier that messing with the gun.

 

[nicholst55]

www.cylindersmith.com; around $35, including return shipping.

 

[rcmodel]

I think sizing the bullets would be the logical thing to do.

If you ream the throats to .309", it will forever be too big for normal .308" jacketed carbine ammo.

Blow-by will increase cylinder gap blast, which it certainly doesn't need any more of!
And accuracy would suffer.

rcmodel

 

[zxcvbob]

If you ream the throats to .309", it will forever be too big for normal .308" jacketed carbine ammo.

Your probably right. But I was gonna ream the throats to a taper from about .309 down to the existing .3075 (or whatever it is.)

I don't think that would cause a problem -- but if it did it's awfully hard to unream it.

 

[Jerry M]

Carbine round was not designed for lead. I doubt the revolver will handle lead very well as a result. High pressure and small diameter bore are going to give you problems.

Good luck