nambu 8mm

[turtlezx]

anyone making this brass
only saw rcbs dies $180.00 !!

[Gunor]

Google the process.
Cannot remember, but process included - .357 Sig (or 40 SW) brass, 8mm Nambu dies and 30-30 dies.

Buy new Wolfe springs for the Nambu

And I bought a box of Larry Potterfields boxes of ammo, a long time ago.

[bullet maker 57]

I made it out of 40 S&W brass, using 8mm Nambu dies. Go slow with a little Imperial sizing wax. 1 out of 10 would not chamber.

[Thin Man]

When I needed this caliber of brass there were none anywhere for sale. Dies are CH4D from Buffalo Bore, but they show out of stock at this time. You might call them to ask about ordering this caliber set and to hear about their price. I found a used NEI mold on ebay, makes very fine boolits - correct nose profile, diameter and weight. I started using 40 S&W brass for this conversion, then found 357 Sig brass was much easier to get a quality final product. A machinist friend made me a "blank" shell holder - flat and smooth on the top to push cases completely into the sizing die, then remove them with a brass rod from the top. Works like a champ with modest lube on the brass, too much lube gives up dimples. After forming the shoulder the rim and web areas have to be reduced to get the cases to fall into the chamber, also to reduce the strain on the extractor. Didn't want to tear up the pistol as replacement parts are sorta rare, don't you know. My load development involved Unique powder, just enough to cycle the action.

If you can stand the strain, Grafs has new brass headstamped HDS (Huntington Die Specialties) listed at $72.99 per 100 pieces. HDS themselves also lists this caliber in stock at $37.98 per 50 pieces. IIRC, street rumor had it back in the day that these cases were actually manufactured by Starline but they do not show this caliber available in their listings today. Could be a trade agreement for no competition with HDS, but then how did Grafs get their supply? Whether you convert 357 Sig brass or buy ready to go brass, you still have to pony up for dies. Any time you get involved with a rare caliber project (does 375 Winchester empty brass come to mind?) prices are whatever the buyer can tolerate. Good luck with your project.

[salpal48]

Graf still has them made by Starline under contract

[skeettx]

https://www.grafs.com/retail/catalog/category/categoryId/500?

https://www.gunbroker.com/item/737047344

For a set of dies there is one currently on auction for $20
item number 112754076931

[GONRA]

Decades ago GONRA made 'em (home made dies)
from .35 Remington rifle brass, then .41 long Colt revolver brass (much better)
finally got RCBS dies, Midway and FC factory brass cases (best of course).

[pee-wee]

I make nambu brass from 357 sig.....when sizing in your nambu size die the 40 case necks split because of the large size reduction...where as using the sig case you are almost where you want to be size wise.....also when using sig brass one has to reduce the diameter of the case rim.
I chuck the case in a drill press and reduce diameter with a file measuring with calipers...

[RED BEAR]

midway sells nambu brass.

[Sanchez]

Have used .40S&W as well, & for quite a while before .357 SIG was released.
Avoid neck splits by annealing the cleaned cases before sizing.
The .40's fat rim needs to be thinned-down as well, plus the head diameter needs reducing a bit - the only sane way for these 2 ops is by lathe.


I make nambu brass from 357 sig.....when sizing in your nambu size die the 40 case necks split because of the large size reduction...where as using the sig case you are almost where you want to be size wise.....also when using sig brass one has to reduce the diameter of the case rim.
I chuck the case in a drill press and reduce diameter with a file measuring with calipers...

[rrob692326]

Use CH dies, cheaper and very good quality I use a cut off the top 30/30 sizing die, with a lee push through bullet ram and imperial sizing die wax. With this setup you don't ever have to pound the 357 sig brass back out with a hammer, you put the lubed 357 sig case on top of the ram lower your press handle and push it through they just pop out the top of the cut 30/30 die perfectly sized outside dimensions with no trimming or grinding necessary ready to go to the next step no fuss no muss. There is also a guy out there that makes nambu extractors you just send him your top half of your nambu and a sample of you converted 357 sig brass nambu cases with the standard unaltered rim and he will fit your new extractor to your pistol so it works perfectly with the thicker rim of your made brass, and you can save your original extractor for later with factory brass. He charges a reasonable 4o bucks. Here is his information a real good guy. If I can be of anymore help please let me know. Don't forget to anneal your necks as the brass will last much longer.
Don Schlickman
1470 Wood St
Dubuque, IA 52001-4256
E-mail: dfsjpn@aol.com
Phone: (Home) 563-556-8496
(Cell) 563-580-4220

[Happyguy]

I used 357 Sig brass, run the case up into a 30-30 sizing die until the rim/head is the correct diameter. I used a steel rod to knock it out. I fabricated a rod to push the case up into the 30-30 die. Then run the case through the Nambu sizing die. If I were to do it again I would have Lee make the correct sizing die for reducing the rim/head diameter. David