New RBH has tight chambers!

[DanM]

I traded around and ended up with a very nice Blackhawk in .30 carbine. A revolver that has been high on my wish list for some time. This one is like new, and very tightly chambered. I think too tight for cast boolits. Chamber throats will just barely pass a .308" bullet. I had to tap on some to get it through. I did chamber casts, and all were just .308". Bore is .308". Also, I will have to trim my brass shorter for the rims to clear the breech face. all my new and used .30 carbine brass measures 1.287-1.290", they are too long, and rub on the breech. Even some factory Remington ammo will almost lock up the cylinder. I ran a box of Remington 110 ball through it saturday, and probably a half dozen wanted to lock me up. I am testing different lengths of trim. If I trim to 1.272", that puts the bottom of the rims flush with the rear of the chamber, which probably leaves a little too much gap between the cases and breech. Trimming to 1.281" seems about right, as it closes the gap some, and case heads don't drag. I will put the feeler guages on it tonight and measure the gap I am getting more closley.
So....I am wondering....(1) Is there an optimum gap to shoot for when I start trimming cases? I am talking about the gap between the rear of the case and the breech face? and(2) Advice on honing these throats to .309" for cast bullets.
I know Ruger has good customer service, but in this case, I think they would say that the cylinder is "within spec", and not work on it.

[nicholst55]

Check out www.cylindersmith.com. Not sure if he does .30 throats - I think he does. I have no experience with the .30 Carbine in any type of gun, but I'd be concerned if factory ammo caused cylinder rotation problems.

[USARO4]

I have a RBH in .30 Carbine, it's one of my most accurate revolvers. It also has very tight chambers. My solution is to trim cases to 1.280" then seat boolits and crimp with a Lee FCD in two seperate steps. Also make sure your chambers are cleaned of any oil leftover from cleaning and storing the revolver, they should be totally dry. I shoot cast 99% of the time in this gun. I size the boolits to .308".

[DanM]

Thanks for the link. I sent them an email.

[DanM]

I have a RBH in .30 Carbine, it's one of my most accurate revolvers. It also has very tight chambers. My solution is to trim cases to 1.280" then seat boolits and crimp with a Lee FCD in two seperate steps. Also make sure your chambers are cleaned of any oil leftover from cleaning and storing the revolver, they should be totally dry. I shoot cast 99% of the time in this gun. I size the boolits to .308".

This sounds like a good solution. You are getting good results with .308" sized boolits? That is good news. I will try some before working on the throats. Which molds do you like for this application? I am looking at the Lee C309-113-F, and the Lyman #311359.

[USARO4]

I use the Lee C309-113-F, I wish I had got in on the 6 banger group buy for this mold, maybe we could start another one. For screaming loads try AA#9 powder.

[DanM]

I would go for one of the 6 holers if there was enough interest for a group buy. Otherwise I will just get the 2. Yes, AA9 is my favorite powder for .30 carbine in the rifle. Will be the first powder I try for pistol loads.