How much brass movement?

[Wayne Smith]

in reforming brass. I may have the opportunity to revive a drilling that's apparently 16x16x9.3?x?. It was made in Moldovia(?), Stettin, when it was in Moldovia. I've been looking at the rimmed 9.3's in COW and wondering from what could I make brass?

I'm guessing the critical measurement is base diameter, and my question is: How much is reasonable to expect to be able to change base diameter by reforming in a die? So far I'm looking at ~.04" oversize if I remember right. (I'm upstairs at the computer, all the data is downstairs, and I'm on crutches for the next 6 weeks) That's using .405 Win brass, and maybe a little less if I can find .40-90 brass (no, I haven't yet checked Buffalo Arms - I will).

My question is, is it reasonable to expect to make brass that will fit when I start with a ~.04" oversize base? What are the tolerences for starting with undersize brass and fireforming? Again, I'm talking base diameter. Everything else is much more amenable to change.

Yeah, I know I'm likely to have to turn down rims.

[Wayne Smith]

Here are the cases I'm looking at:

2 possible chamberings

(Base Diameter Rim diam. Rim Thickness Length)

9.3x72 Saur

.473 .518 2.83

9.3x74R which may be available, but with Boxer primers?

.465 .524 .052 2.93


Two possible existing cases (American)

.405 Win

.461 .573 .075 2.58 (will be short)

40-90 Sharps Straight

.477 .546 3.25

Is it reasonable to make either of the first two from either of the second two?
The only case forming I've done to date is from 30-06 to 8mm-06, no big challenge!

[NVcurmudgeon]

Wayne, Have you made a chamber cast yet? Here's hoping finding cases will turn out to be easier than you think.

[StarMetal]

If you're talking about the solid part of the case, the part which only the primer flash hole is punched or drilled through, is .04 over size, then that's waaaaay too much to size down with standard reisizing dies. On a phone conversation with Dave Chabins, that owns CH Die Co., he told me to size a base down .001 requires a dies with a wall thickness of 1 inch !!!!. I made a friend of my Dads 8mm Mannlicher brass out of 8mm Mauser brass and boy ole Dave was right. I couldn't get the bases sized down and they only needed to go a wee bit. Ended up having to machine them down.

Joe

[carpetman]

You cannot call this brass movement---the initials for that(BM)are already taken and it would cause mass confusion.

[Blackwater]

Wayne, first thing to do is to get some Cero-Safe and do a chamber casting and find the chamber dimensions, including rim dia., rim thickness, base dia., dia. at shoulder, length to shoulder from base, neck dia., length from base of rim to base of neck, and OAL. Slug the bore, too, while you're at it, but if your chamber casting includes a bit of the rifling, you can get that from your Cero-Safe casting too. Then call Buffalo Arms and see what they'd recommend, based on your measurements. They're one of the very few folks that MAY (???) go and actually measure some cases for you. This would simplify things for you.

BTW, quite a few years ago I did something similar, but can't remember the caliber. I think all I did was some leg work and a bit of advising for someone with an old rifle not unlike yours. I know from a small amount of experience that:

A. You can thin a rim, but you can't effectively add thickness to it;

B. You can cut a too wide rim down in a lathe or even a drill press easily;

C. A slightly undersized case body CAN, if it's not TOO far undersized, expand to fit a larger chamber. They won't take high pressure, but I'm doubting you're considering that with your project anyway???

D. A buddy who used to have some nice old black powder express double gun could actually size the soft brass he had without using a sizing die by just using the rotating forearm lever locking device to "size" the cases enough to chamber well, but your gun is a break-top, which won't do that, right?

Those old drillings can be REALLY neat guns. I have yet to pick one up and not have it captivate me. Amazing how light and well balanced and good-swinging they can be, isn't it?

I'd bet a dollar to a donut that there's something you can make brass from, if you can just identify it, or at least get those dimensions.

[floodgate]

Wayne:

There are two likely candidates: the 9.3 x 72R, a straight-taper case 2-7/8 inches long, and the 9.3 x 74R, just a hair under 3" with a slight bottleneck. There should be a couple of numbers stamped in proof on the frame flats under the barrel, or on the bottom of the barrels themselves, which can help the ID. There are a few other possibilities, but those are the most common "Drilling" 9.3's. I've got some pretty thorough references, and Barnes' "COTW" has some good tables of dimensions. The 72 mm case is roughly equivalent to the .38-55 in performance (longer case, but lightly loaded); the 74 mm is in the .35 Winchester league...Cases and loaded ammo are available for both of these, though you may have to contend with Berdan primers.

(BTW, someone asked yesterday or today what it was the .35 Winchester; it was a necked-down .405 Win., and both derived from the BP .38-72 and .40-72 rounds for the Hi-Wall and the '86).

My Dad brought a 16 x 16 x 9.3 x 72R back from WW twice, and I scrouvenged up two cartridges for it - shot it once and saved the other, later traded it off for I fergit what (GRRR!). I'd swap all my guns for a good "Vierling" in 16 x 16 x 7mm or 8mmR with a .22 LR barrel buried in the middle or in the rib, and a .380 ACP (9mm Kurz) in a trap in the butt. Any takers???


Ennyhow, send me any dimensions or numbers you can find and I'll look it up in my library. (I've spent more on books than on guns, ammo and reloading gear over the years, all together, and I feel obliged to "share the wealth").

floodgate

[Wayne Smith]

This is really preliminary, as the gun is still across country and I probably won't see it until Thanksgiving. I'm more interested, at this juncture, in what is and is not possible.

Thanks, Starmetal, I think you answered that one.

[Ed Barrett]

If all else fails you can have a good machinist turn you a few shells from solid brass stock. I had 8 shell made for me for an old rolling block I picked up. I loaded them pretty light with both black and smokless and reloaded 4 of them about 40 times and sold them with the other 4 virgin shells when I sold the rifle.

[Char-Gar]

George Nonte in his book Cartridge Conversions writes of RCBS base forming dies that can reduce the diameter of the 30-06 base to .444 that is a reduction of .024. I don't know how much more you can take a case head down.

In the same book he gives specs to form 15 different 9.3 cases, If you case has another name, or detailed specs, I might find some helpful information.

[Ross]

The most commonly found drilling 9.3's I've run across were 9.3x72R. There are at least two versions of that name, Sauer and Normal. Rim thickness seems to be a major distinction
Both RWS and Norma make 9.3x72R brass. Bertram makes .30-30 3¼" basic brass that may be useful to convert, as it is only about .007" shy at the base.
Old Western Scrounger had loaded ammo, so I suppose Navy Arms has it now.
Cheers from Darkest California,
Ross

[Wayne Smith]

Thanks, all. I've got Amazon.com searching for Nonte's book. Needless to say, it's out of print. Once i get the gun and can do some casts I may be back to you, Chargar, if they haven't come through with a copy for me yet.

This is one of the reasons I like to think ahead. All too often the information/resources needed for a project like this are difficult to find.

[drinks]

Wayne;
The" Handloader's Manual of Cartridge Conversions" is still in print and is much more through than Nonte's.
I have both and have used both, but the Handbook is more useful.
Don