8mm Nambu Loads

[cuzinbruce]

I dug around a bit and found my 30/30 dies and gave this a try. It works. 40 S&W into 8mm Nambu. Cases are a bit long and should be trimmed. Compared to my one original Nambu cartridge, these are longer and have a thicker rim. Rim is a little bigger and so is the base of the cartridge case, just ahead of the extractor groove. It took a lot of pounding getting each case out of the die after forming the base. CH Jr Champ has compound leverage so it wasn't that hard forming them. Tried Imperial lube, then went to lanolin. In my RCBS primer pocket swage set there is a cap that fit over the ram nicely. Tomorrow, I am going to trim them and see how they fit in a gun.

[cuzinbruce]

They don't fit. Too large at the base.

[Ed in North Texas]

They don't fit. Too large at the base.

PM Buckshot for a push through.

[Gunor]

Old Nambu thread - Can I use a .410 Lee Push thru sizer for the final sizing of the case head?

Geoff in Oregon

[Gunor]

Attachment 147691

Midway Loading Data

[01SVTvert]

Bumping an old thread as I just acquired two type 14s and intend on shooting both. Going to get Wolff springs and hopefully find factory ammo but I want to reload at some point. Question is whether buying a set of $150 dies makes sense for a pistol I may not shoot a lot.

Any new info out there on reloading the nambu?

[Lostinidaho]

I enjoy shooting and reloading my Nambu. Its accurate. Meaning, I can hit the steel target I am shooting at. It is pleasant to shoot. It doesn't jam all the time like some say. Making sure I collect all my brass is the only bad part. Brass is the expensive part of shooting this firearm

[Greg G.]

Found this thread interesting. I started to reload for my Nambu about 2 years after Larry Potterfield started Midway by doing the same thing, unbeknownst to me then. Back then I could not fine a mold and the RCBS made the only die set that I could find, this is before the internet. Made my boolit mold from a mold for a 180 gr. 8mm, cut down to cast 102 gr./ .323 and sized to .320 with a custom Lee sizer and tumble lubed with Alox. Used 32 ACP data as a starting point to work up to a load that was half way between just starting to make the gun cycle correctly and first signs of high pressure. BTW didn't have any .40 brass then so used .38 super, sized, trimmed, and fire formed using my starting load. After that all loads were my mid point load, makes a accurate load and worked well in my gun. Now I use the .40 brass and the 30/30 die trick now.
Greg

[01SVTvert]

30/30 die trick is going to be my go to I think as I need to start reloading for 30/30 anyways. Thanks for the new input, keep it coming!

[shortfal]

I have a Nambu upper with bolt but not the rest of the gun.
Should I put on the swap/sell section?
Pete

[xjda68]

On the 83 grain .320 diameter bullets from Graf. I loaded them using the chart that was posted below with 2.7 and also 3.0 grains of Unique. They would not function the slide on my Type 94. I keep increasing the load by 0.5 grain. Finally at 4.5 grains of Unique it functions the slide fully. Now the caveat is your milage may vary depending on what type of Japanese 8mm Nambu pistol you are shooting, and you spring tension. My recoil spring feels fairly stiff when retracting the slide by hand.

[Japlmg]

357 Sig brass is easier to reform than 40 S&W.
Run the case all the way (flush with the die bottom) into a 30-30 sizing die first (remove the decapping rod completely), to slightly reduce the case diameter, then knock the case out of the 30-30 die with a punch.
Then resize using the 8mm Nambu die.
Trim to length, and then reload as normal.

[garandsrus]

I used both .40 and 357 Sig and there wasn’t any difference in forming. I did make a push through die.