Romano Spencer and Rocky Mtn. brass trimming

[El Supremo]

Hello, everyone:

New here, but a graybeard with blackpowder, etc.  I lucked into some of Larry's stuff and am getting ready to load for the 56-50 using CH4D dies, Rocky Mountain's turned brass and Larry's bullet, sized to .512" in my Star sizer.

With the help of many of the postings here, I've located a chamfer/debur tool, priming tool for the CH4D #57 shell holder and a Forster turning tool with a diameter that will work with the roughly .530 case neck OD.

It may be a week or more before I can size the new brass and measure the SIZED case neck ID and order a pilot for the Forster tool.  OK, I may not have any stretch, etc, but it seems to me that at least to begin, I should have the case mouths trued.

Would someone familiar with these particular cases in Larry's Spencers please let me know what trim-to-length pilot OD I'll need for the Forster tool?

Also, my experience with BP in both muzzle loading rifles and BP ctg. guns is that the black should be SLIGHTLY compressed for optimum accuracy.  I want to emphasize SLIGHTLY.  Larry suggested 3FG loads of between 35 and 40 grains and then his bullet with a LITTLE crimp.  Would such a load be compressed?  If not, does it need to be, perhaps via a vegetable wad under the bullet?

Many thanks in advance.

Kevin Tinny

[Bead Swinger]

Kevin
I'm not a 56-50 shooter (at least yet), but I did a lot of shooting with 56-56; I couldn't get much more than 33 gr without significant compression.  I suspect that you won't get 35 gr. without significant compression.  I'd love to be wrong, though.

'Good luck - would love to hear how she shoots. 

[Fox Creek Kid]

Actually, the RMC brass holds MORE BP than Starline or Bell based cases. It also takes a pistol primer and not a rifle primer. The only downfall is that I had to tumble mine in ceramic media for 24 hrs. to polish the small concentric machining rings off the cases as they were almost impossible to eject after firing. These rings gripped the chamber walls like glue.

[El Supremo]

Thanks, Bead Swinger and Fox Creek:

According to Rocky Mountain, its turned brass for the Spencer can be ordered with primer pockets being for either large pistol or large rifle primers.  Larry orders his for large rifle and the stuff I have is for large rifle.  It's so pretty that I hesitate to use it. 

I'll look at the virgin cases from Larry again, but they didn't appear to have turning rings, but my eyes aren't what they used to be.  My quick look a day back revealed that they appear to have been polished during machining, possibly with either wet-dry or steel wool.  I'll polish a couple with 4-0 steel wool and see what's there. 

Interestingly, I've learned that chambers and cases can be too smooth, at least with modern, centerfire rifles.  Polishing chambers to a mirror finish and doing the same thing to cases for the likes of benchrest shooting can lead to what the experts describe as increased surface area via flatter contact surfaces.  This has caused extraction problems.  I doubt this would be an issue with low pressure black powder loads, especially the likes of the relatively anemic 56-50. 

I have a Dillon 750 vibratory tumbler and have used the "green" Lyman media for some time with no problems for other brass.

Will CERAMIC media work in a vibratory tumbler or should I try it in a rotating version, please?  Thanks.

I really appreciate the helpful comments and will look closely for the turning marks being a potential problem and report back in a few weeks on that topic.

Regards,

Kevin Tinny

[Fox Creek Kid]

Ceramic media is too heavy for a vibratory, however some people still do it. You have to use it wet and not only is there a huge load bearing weight but the danger of electrocution if you have seepage. I use a lapidary grade tumbler from Lortone.