I have 60 pcs of RMC I bought this summer and I am very happy with them. I need to order 100 more and they will be expensive, but they work well and have the correct head stamp on them for my 40-70 Ballard.

I tried some 32-40 RMC cases several years back a friend gave me six. Three with small rifle primer pockets and three with large. I lost all but one on the first firing and kept it for a seater case. I later found out that when ordering one should also send in a chamber casting along with the order to keep this from taking place. A bit off topic but probably something to think about if deciding to order some turned cases for yourself.

JLouis

uscra112 wrote on Dec 29^th, 2018 at 2:36pm:


What about the inside of the case?  Seems like that would be more difficult to polish.

Why don't the brass turners set up to draw a basic brass that can be formed into a few specific obsolete cartridges and trim the rims and base thickness as necessary?   

I've made a lot of turned brass since I bought my 30/40 HW, in 1985. All have been to reduce case capacity. I've also made them for 308, 32/40 and 45/70. The materials that I used are, brass bar stock, 304 SS, bronze and aluminum bronze.

My stainless steel case, lasted about 13 years and probably, well over 1000 rounds, all breech seated and was not polished, inside or out. It's end came after the neck lost it's seal and collapsed. I was able to expand it back out but, after about 50 more rounds, it collapsed and split. It's not the best material but, it worked. It was just 1.8cc capacity. The next one was a bronze case, that I made to 2.8cc for fixed loads, it was polished, as I had to do the final fit, inside the neck and out. I made it that same year of '85 and used it until I "rung" the chamber in about 1990. It never failed and I still have it.

I made a 32/40 out of brass, for shooting fixed, I did not polish it. It lasted one shot, as the finish left by the chucking rear, was rough enough for the bullet to just grab it and pull the neck off.

The 308, I made for a friends Bolt gun, with a small rifle primer and with a polished inside neck. It lasted a few months and then he double charged it, with faster powder and opened the primer pocket to at least 1/4 inch.

My last case was made from aluminum bronze (an extremely tough material!), for my rechambered, to 30/40 Imp. I only have a few hundred rounds through it but, it works like a dream. It's also a reduce capacity case with a reamed .3115 (dowel pin reamer) hole back to within .3 of the case rim and a SR primer pocket. That case has shot some fantastic groups, including a 10 shot 1.288 group @ 200 yds.

Things I learned:

Polishing the outside of the neck, isn't need for low pressure loads but, I would recommend it. IF your brass fits the chamber neck. By that I mean that it should be the same size as the chamber neck or, even a push fit. It will spring back to the right size, if a push fit.

The inside of the neck should always be polished, especially if you want to ever shoot fixed or, BP.

Behind the neck, isn't that important, as long as it's a fit similar to a factory cartridge. It will take the shape of the chamber, over a few shots.

Case heads should be at least .25+ thick. You have to be careful here, as decapping pins are only so long. My .30 case head, barely decaps. The thicker the case head, the stronger the case.

Continued:

Here are a couple of turned cases for a personal project with necks of 45 thous. and worked just fine. And another turned case project on the bottom with a 25-20 case next to it for comparison sake and .321 fixed project that also works fine neck is 15 thous. and non are annealed or inside polished just machined very nicely.

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Sounds like you are on to the solution Frank.