VZ-52 / 7.62x45 from PPU Blanks - Part II

I got a few hundred of the PPU 7.62x39 Blanks to play with and so far the results have been good. I've fiddled with my process a bit and I think I have it down to a workable process. No machining required.
1. Modify a Lee Decapping die by grinding the decap pin into a smooth, sharp point.
2. Push each case up into the sharpened and polished decap pin point carefully guiding the point to the center of the crimped blank
3. Dump powder
4. Remove primers. My batch of primers came out and went back in very easy.
5. Use a mini cut off wheel to cut the crimped blank portion of the case off. This is very important to cut just the correct amount. Too much and you end up with a very short neck. Too little and when you size them the case neck will split and make the case unusable in 7.62x45. No wrinkle or tear from the crimped blank end should be left. If you Cut them too short throw them in a pile and cut them back even more to use as 7.62x39's.
6. Don't bother to trim them all nice and pretty yet,
7. Lube cases inside neck and outside
8. Gently size. Don't slam the press arm or you will get a tear in the case neck.
9. Now inside neck chamfer
10. Tumble to remove lube and chips of brass.
11. Re-prime
12. Charge with 25g of IMR 4198 or 11g of Trail Boss. I'm sure others would work. I tried using the blank powder and Cream of Wheat with zero success.
13. Seat a 125'ish gran bullet of .308 or so diameter. You can seat these to a standard length or seat them a ways out.
14. Single load a round and try to fire it. If it fires great, try loading a few in the mag. The 4198 load will cycle the gun and 9 times out of 10 form a nice case. The trail boss load won't cycle but you almost never ruin a case. If your round does not fire you may need to carefully place it under the extractor and gently chamber it. The extractor will hold the case well enough to get it to fire. Seating a bullet with a fat profile far enough out sometime will do this for you. But bullet profiles vary and some won't push the case back up against the breech face no matter how far out you seat them.
15. Now Tumble, Lube, Resize, Trim as normal and you have usable 7.62x45 brass with no machining required.
Don't worry about them getting trimmed below 45mm. I've had cases down to 43'ish mm work and load just fine.
Attachment 289860

For your first sizing make sure your cases are adequately lubed, place them in the shell holder, and gently push them into the die. When you get significant resistance remove the case, turn it in the shell holder, and repeat. This will prevent the neck splitting most of the time.

Quote:

---

Originally Posted by Wayne Smith

For your first sizing make sure your cases are adequately lubed, place them in the shell holder, and gently push them into the die. When you get significant resistance remove the case, turn it in the shell holder, and repeat. This will prevent the neck splitting most of the time.

---

I'm using Imperial Sizing wax, so you really don't feel much resistance. I have tried going 1/2 way and turning them. Mixed success. The main culprit of the tears seems to be some tiny left over wrinkle from the star crimp. If I get every last trace of that crimp removed they don't tear. I'm not super stocked up on 7.62x39 brass . . . so turning the few torn cases into 7.62x39 is not exactly a tragedy for me.

Thanks for the input.

Yes, that's exactly the problem. If you have a nick in the neck, or even an uneven area, you will get a split or streak.

Would annealing before expanding the neck help with tears or splits in the case mouth?

Quote:

---

Originally Posted by NuJudge

Would annealing before expanding the neck help with tears or splits in the case mouth?

---

No, you have to have the mouth trimmed clean, with no bend or nicks - any damage to the mouth of the case translates into case failure along the neck.

Instead of modifying a decapping pin, dumping powder, etc., why don't you just run the loaded blank through the 7.62X45 sizing die , chamber it, and fire the blank thereby fire forming the brass? May not even have to run through the 7.62X45 FL die first. Then trim to length and load normally.

The 7.62x39 blanks shoulder won't allow it to fire in the longer 7.62x45 chamber.
.30 Remington brass is too narrow at the case head to work.
PPU could make new brass for it instead of 8mm Lebel for goodness sake[emoji848]

Sent from my SM-A716U using Tapatalk

If the shoulder for 7.62X39 is too large, that's why you would run a loaded blank through a 7.62X45 FL die first - then it should chamber okay. I've run thousands of .30/06 blanks through an 8X57 mm FL die (plus another neck die) to make Mauser blanks.

What I meant is that the head to shoulder distance is shorter on the x39, preventing correct headspace to fire the shorter cartridge. The extractor might hold it tight enough to fire and it might not.....
But the OP has it figured out, so I would follow his lead on this if I still had a CZsHe52 to shoot.

Sent from my SM-A716U using Tapatalk

Okay, I understand. That being said,I have seen people shooting 7.62X51mm blanks in an 8mm Mauser before. Some required being run through an 8mm FL die because of base brass dimensions, but they mostly were just being held by the extractor.

As you note, it's moot as the OP already has a forming process that works.