Darin's 7.62x45 Czech fabrication guide

Bullet info: .310-.311 123 grain bullet, my Czech VZ-52 rifle bore mikes out at .310.

Bullet choices: any standard .310-.311 bullet meant for Warsaw Pact AK-47/SKS rifles. Hornady, Speer, Sierra, Winchester, Remington, and IMI all make 123 grain bullets for this caliber.

7.62x45 brass dimensional data (listed from Military Cartridges of the World)

case length = 45mm (1.771 inches)

neck diameter = .334 inches

Shoulder diameter = .412 inches

Base diameter = .441 inches

Rim diameter = .440 inches

Cartridge OAL = 2.36 inches

Head end of cartridge approximates dimensions of sibling cartridge, 7.62x39 Soviet.

Case forming technique:

This has become quite simple since the first version of this page. Begin with new 6.5x54 Mannlicher-Schonauer brass. If new brass is not available, anneal used brass to allow SERIOUS case mouth/shoulder modification. Take your time, and don’t be discouraged if you crumple your first few pieces. Chalk them up to a learning experience and press on.

1.  You’ll need 7.62x45 Czech dies. Currently, only RCBS makes them. You might be able to use 7.62x39 dies in a pinch, but setting the shoulder length would be ticklish at best. Since final fireforming sets the proper taper and shoulder fit to the chamber, the proper dies would still be the best option after the first firing of the newly formed brass, to avoid stressing it on subsequent reloadings.

2. A hacksaw and a vise are one of the first tools needed. Take that beautiful 6.5x54 M-S brass, and cut off the neck as well as approximately 1/4 of the shoulder. This should leave a shoulder showing with a .30 caliber-ish hole at the end of the shoulder. I went to this technique versus the original 6.5mm expander and case trimming routine when I noticed how much easier the process was. Deburr the brass mouth, and you're ready for the next step.

3.  Now, adjust your 7.62x45 resizing/decapping die to proper sizing depth, and lube the brass (SPARINGLY!), inside and outside. Don’t forget to clean out any brass shavings that may have accumulated inside the neck area of the brass. With a firm pressure, run the brass all the way through the die. If luck was with you, you’ll have something resembling a 7.62x45 round, save for the long neck. With the case trimmer, trim the brass to the proper 1.77 inches.
 

 

A fuzzy photo of the steps, left to right, of .220 Swift to 7.62x45 Czech
(Old technique, new photos in the works for 6.5x54 M-S conversion)

4.  ANNEALING: I consider annealing this new brass important, especially if you intend to reload it more than once or twice. I use the propane torch and pie plate method for annealing. This method is listed in several reloading manuals, and gives me a finished product that looks very similar to issue military brass, right down to the color of the neck and shoulder. Simply stand the brass to be annealed up in a pie pan or suitable dish, adding water 1/2 way to the shoulder. With a propane torch, simply heat the case mouth, neck, and shoulder until a dull red glow is visible on the case mouth. Quickly tip the brass over in the water to quench it, and repeat with all the brass until done. This process will extend the life of the brass considerably.

5. There! You made 7.62x45 Czech brass. I’m still working on a proper crimping operation, for now my Lee factory Crimp die for the 7.62x39 Soviet is pulling that duty, but barely. There is only 1 published load for this round, from Cartridges of the World, and it lists an IMR 3031 load behind a 130 grain .308 bullet, definitely not optimal for the .310 bore. I have begun to use the load data for the 7.62x39 Soviet round, with the 123 grain bullet, as the cases are almost identical, save for the 6mm-length difference. A starting load of 26.0 grains of Accurate 1680 delivered a mild-recoiling round that cycled the rifle’s action well without beating up the brass at all. The only problem with the load was that the bullets keyholed into the target at 50 and 100 yards. Velocity was a paltry 1800 fps out of my VZ-52. After working up this load, I am now using 28.0 grains of AA1680 as my load of choice. Velocity was 2350fps, and accuracy improved to 3" at 100 yards. AA2200 is another promising powder for this cartridge and the 7.62x39. As I get more loads safely built up, I’ll report on what I’ve found.