7.62x39 cast bullet load data

[Kosh75287]

I found some AR barrels that had .308 groove diameter with a 1-10 twist chambered in 7.62x39, just like the original Mini 30s. The older die sets came with a 308 expander ball. I had one of these ARs before and developed a 150 grain load using H-322. The load makes a similar round to a miniature 308 Win. The hard cast and powder coated plain base RCBS 150 or 165 style flat point should do real well with the 2,500 fps load.
I prefer the AR platform with a straight 10 round mag.

RAPIER, I'm a little confused. Are you saying you can get 2500 f/s with a 150 gr. cast in a 7.62x39, without straining things? Are the barrels you are using somewhat longer than the 16.5" AK/AKM pattern barrels?
I looked up data for 150 gr. projectiles in the 7.62x39 using H322, and Hodgdon lists 28.5/H322/150 gr. Hdy. SP as giving 2192 f/s from a 24" test barrel. Granted, the projectile listed by Hodgdon was a j-word, while you will be using PC'd projectiles, but will the added lubricity of your PC'd rounds get you another 300 f/s from similar or shorter length barrel?

I checked data using AA #2200 and found that 29.0/AA#2200/150 gr. Sierra SPT gave them 2291 f/s from a 21" barrel, which is closer to your goal, but still 8% under in terms of velocity.

This isn't a criticism, so much as my expressing concern that you might be pushing the limits of the platform, as you try to obtain "miniature .308 performance" from it.
I had a Czech Vz-52 rifle in 7.62x45 with which I experimented, and found that I could improve on the AK round by ~125 f/s in the same bullet weights. I got nowhere near a .308 nor even a .30-40 Krag, before getting pressure signs.

[405grain]

That 2500 fps figure sounded fishy so I ran the numbers on Gordon's Reloading Tool. Using a 155 grain cast bullet in the 7.62x39 with H322, to get a velocity of 2500 fps you would need a charge of 33.5 grains. This would give you a pressure of 82,912 psi. The maximum pressure for this cartridge is 51,488 psi, so this is a 31,424 psi overcharge! I seriously doubt that 33.5 grains of H322 would even fit in the case since the absolute maximum pressure load for this bullet/powder combination is 29.5 grains, and this would only give you a velocity of 2149 fps. (please note: I consider ALL of the loads that I just posted to be too high, and would consider them unsafe. I have only posted these loads to show that the claim of acquiring 2500 fps from this cast bullet/powder charge in 7.62x39 is unrealistic.)

[dondiego]

I used to shoot the Lee 155 gr. bullet but have since moved on to the Noe 129 gr. sp bullet and a NOE Ranch Dog 150 gr. bullet in both my Yugo SKS and my Ruger American and CZ 527. The Noe 129 gr. is a great all-around bullet for general shooting and the 150 Rd shoots well also while really hitting hard. I PC and gas check the bullets and they work great.

Recently discussed the 150 Rd in this thread: https://castboolits.gunloads.com/sho...9-to-hunt-deer


In the pic below L to R:

The NOE 129 gr. SP back before I started to PC
Lee 155gr. I used to use
NOE 150 gr. RD

NOE 129 gr. SP loaded
NOE 150 gr. RD loaded



Attachment 309260

Ha! I just glanced at your picture and I saw the blue projectiles and I immediately thought that they were inert military 40 MM stuff! I have some on my shelf!

[groovy mike]

I have found some decent loads using 2400 and 3031, but nothing that is really a tack driver. BLC2 works well for jacketed bullets. Since I have a couple of pounds on hand I'm wondering if it would work for cast boolits too?????

[armoredman]

Holy resurrected thread, Batman! But sure, why not? Can you find plated data for that powder? If so, use plated data for powder coated cast boolits. If you can't find any data, try writing the company.

[6622729]

Look up something like "single caliber manual 7.62X39". It was a booklet you can purchase but these days at least two sources have it posted online for free. I am casting 132-160gr boolits (NOE and Lee molds) for 7.62X39 and reloading Berdan primed steel cases. In fact I just saw I use the Lee 160gr round as my Avatar. I'm shooting 200yds in two different Howa mini 1500 bolt guns on 6"-12" diameter steel targets and have a lot of fun. It's cheap entertainment.