Several people from my club ask me to do a detailed write up on how I make non-magnetic 7.62x39 for indoor range use. I thought I'll just share the knowledge to everyone on CGN.
The idea is very simple, take a surplus round, pull the evil-commie-baby-killing bi-metal/steel core projectile, replace it with a non-magnetic projectile.
The ammo I made are:
Safe to use in indoor range.
$0.40~$0.45/round
I ran over 200 of them through my SKS with 0 malfunction.
Within 25 yard they hit where I aim consistently.
Usual reloading disclaimer: The stuff described below is very dangerous. It will blow up your gun, your house, yourself, and the entire world. Don't do it! Or at least don't sue me if you ignore my warning.
Tools:
Single stage press. I use Lee breech lock press.
Collet style bullet puller. I use RCBS collet bullet puller, with a 30 cal collet. (bought from amazon)
7.62x39 dies
Some cheap 7.62x39 surplus ammo - I use Russian.
Some non-magnetic 7.63x39 projectiles - I use Berry's .310 123 Gr plated SP projectile.
RCBS puller set

Lee Dies

Ammo and projectile

How the puller work: The handle threads into the collet through the body. When spinning the handle clockwise, the collet is pulled into the body by the threads. The body forces the collet to close and grab the projectiles.

Install the puller onto the press

Raise the ram with a cartridge on the shell plate

Tighten the collet by spinning the handle clockwise

Lower the ram. Voila! Projectile is separated from the case. There's nearly no damage on the projectile, so it can be saved for later.

The round after pulling out the projectile:

This process is fast. I clocked 3 minutes 32 seconds to pull 15 rounds.
After pulling all 20 projectiles, I start seating non-magnetic projectiles in.

Half done:

Whenever I'm experimenting with a new headstamp, I always work up the load toward full factory(surplus) charge. In this case, I knew this batch of Russian surplus works well without fiddling with the power, so I left them as is.
This batch of Russian surplus measured on average to 2.189" OAL. I seat mine to 2.185" OAL.


Surplus projectiles are usually much longer than soft projectiles. Soft projectile will seat much shallower for the same OAL. This probably reduces the muzzle velocity, which is a good thing (more on this at the end).
Projectiles compared:

Crimp is optional. I found the Lee factory crimp die does not have much effect on the hard steel case. I don't crimp.
Cost:
Surplus rounds are around $0.23/round delivered to the door these days. I got mine when they were $0.20/rd delivered
I use Berry's plated .310 SP projectile. My last batch from Marstar cost me $406.20 for 2000cnt delivered to the door during thanksgiving sale. ($0.203/projectile).
Previous batch was from Custom Reloading Service in BC. Cost me $135.52 for 500 cnt delivered to the door. ($0.27/projectile)
In total, I spend around $0.40 / round, plus I recycle the old projectile to stuff into brass case for my CZ527.
If you want to start with non-corrosive ammo, they are ~$0.40/round + $0.20 for projectile, so $0.6/shot.
Projectiles:
Conventional wisdom says you need .310~.312 diameter projectiles for 7.62x39. .308 projectile probably won't work as the surplus case mouth is too large for it (remember my process don't size the case). You risk the projectile falling in further causing dangerous pressure. Also it won't engage the rifling as well as .310 hence losing accuracy.
Berry's .310 is by far the cheapest. There's a catch though. These are not FMJ, but plated projectiles. Berry says don't push them faster than 1700 ~ 1900 fps or you risk plate separation from lead core, result in wild bullet hole and keyholing. I don't seem to have the problem inside 25 yard with it sitting on full powder Russian surplus. On CZ527, I have yet to workout a good load with these projectile. Berry also makes 2 types of .310, SP and FP. Make sure you get the SP (spiral point). FP (flap point) won't feed in semi-auto.
Other options includes various Hornady .310 ($0.35 and upward per projectile), Sierra makes 125 gr .311 or .312 projectiles for .303 brit. But they are all much more expensive.
Developing the load:
Whenever I deal with a new batch of surplus, I always start from reasonable load, and gradually work up to the full surplus factory load.
When I switch from Russian to Romanian surplus, I slowly work it up to make sure I don't blow myself up and bullet does not fly funny.
When I switch from Romanian to Chinese, I slowly work up the load.
When I switch from one head stamp chinese to another head stamp chinese, I slowly work up the load...
(See a pattern here?)
Even when I switch between the same head stamp Chinese, but from 2 different crates, I slowly work up the load...you get the idea.
Some of my notes:


For this batch of Russian surplus, I started with 20 gr of Russian powder and gradually worked my way up. After each shot I checking barrel for obstruction.
Bullet Puller and Press:
If I were to buy the puller again, I'd probably buy the Hornady cam-lock bullet puller. Problem with the RCBS puller is that when you turn the handle to tighten the collet, you might end up 1. spin the puller inside the quick change sleeve, or 2. spin the quick change sleeve against some locking pin on the press. First case it won't tighten the collet, second case it might damage the press. Hornady's system work by pressing down a cam to lock the collet. I think it would work far better.
See how turning the handle on RCBS puller can cause potential damage to the press:

It also makes it very hard to spin the puller out later on:

That's all. Hope you found this useful or at least enjoyable to read.
7.62x39 Family photo - From left to right:
1. Russian surplus loaded with soft projectile, no crimp
2. Russian surplus loaded with soft projectile, light crimp
3. Gecko 7.62x39 123Gr brass case ($1.3/round!!!)
4. Barnaul 7.62x39 123Gr non-corrosive??
5. Czech surplus came on stripper clips (got an awesome deal, $100 for 570 rounds on stripper clips)
6. Romanian 7.62x39 surplus

The idea is very simple, take a surplus round, pull the evil-commie-baby-killing bi-metal/steel core projectile, replace it with a non-magnetic projectile.
The ammo I made are:
Safe to use in indoor range.
$0.40~$0.45/round
I ran over 200 of them through my SKS with 0 malfunction.
Within 25 yard they hit where I aim consistently.
Usual reloading disclaimer: The stuff described below is very dangerous. It will blow up your gun, your house, yourself, and the entire world. Don't do it! Or at least don't sue me if you ignore my warning.
Tools:
Single stage press. I use Lee breech lock press.
Collet style bullet puller. I use RCBS collet bullet puller, with a 30 cal collet. (bought from amazon)
7.62x39 dies
Some cheap 7.62x39 surplus ammo - I use Russian.
Some non-magnetic 7.63x39 projectiles - I use Berry's .310 123 Gr plated SP projectile.
RCBS puller set

Lee Dies

Ammo and projectile

How the puller work: The handle threads into the collet through the body. When spinning the handle clockwise, the collet is pulled into the body by the threads. The body forces the collet to close and grab the projectiles.

Install the puller onto the press

Raise the ram with a cartridge on the shell plate

Tighten the collet by spinning the handle clockwise

Lower the ram. Voila! Projectile is separated from the case. There's nearly no damage on the projectile, so it can be saved for later.

The round after pulling out the projectile:

This process is fast. I clocked 3 minutes 32 seconds to pull 15 rounds.
After pulling all 20 projectiles, I start seating non-magnetic projectiles in.

Half done:

Whenever I'm experimenting with a new headstamp, I always work up the load toward full factory(surplus) charge. In this case, I knew this batch of Russian surplus works well without fiddling with the power, so I left them as is.
This batch of Russian surplus measured on average to 2.189" OAL. I seat mine to 2.185" OAL.


Surplus projectiles are usually much longer than soft projectiles. Soft projectile will seat much shallower for the same OAL. This probably reduces the muzzle velocity, which is a good thing (more on this at the end).
Projectiles compared:

Crimp is optional. I found the Lee factory crimp die does not have much effect on the hard steel case. I don't crimp.
Cost:
Surplus rounds are around $0.23/round delivered to the door these days. I got mine when they were $0.20/rd delivered
I use Berry's plated .310 SP projectile. My last batch from Marstar cost me $406.20 for 2000cnt delivered to the door during thanksgiving sale. ($0.203/projectile).
Previous batch was from Custom Reloading Service in BC. Cost me $135.52 for 500 cnt delivered to the door. ($0.27/projectile)
In total, I spend around $0.40 / round, plus I recycle the old projectile to stuff into brass case for my CZ527.
If you want to start with non-corrosive ammo, they are ~$0.40/round + $0.20 for projectile, so $0.6/shot.
Projectiles:
Conventional wisdom says you need .310~.312 diameter projectiles for 7.62x39. .308 projectile probably won't work as the surplus case mouth is too large for it (remember my process don't size the case). You risk the projectile falling in further causing dangerous pressure. Also it won't engage the rifling as well as .310 hence losing accuracy.
Berry's .310 is by far the cheapest. There's a catch though. These are not FMJ, but plated projectiles. Berry says don't push them faster than 1700 ~ 1900 fps or you risk plate separation from lead core, result in wild bullet hole and keyholing. I don't seem to have the problem inside 25 yard with it sitting on full powder Russian surplus. On CZ527, I have yet to workout a good load with these projectile. Berry also makes 2 types of .310, SP and FP. Make sure you get the SP (spiral point). FP (flap point) won't feed in semi-auto.
Other options includes various Hornady .310 ($0.35 and upward per projectile), Sierra makes 125 gr .311 or .312 projectiles for .303 brit. But they are all much more expensive.
Developing the load:
Whenever I deal with a new batch of surplus, I always start from reasonable load, and gradually work up to the full surplus factory load.
When I switch from Russian to Romanian surplus, I slowly work it up to make sure I don't blow myself up and bullet does not fly funny.
When I switch from Romanian to Chinese, I slowly work up the load.
When I switch from one head stamp chinese to another head stamp chinese, I slowly work up the load...
(See a pattern here?)
Even when I switch between the same head stamp Chinese, but from 2 different crates, I slowly work up the load...you get the idea.
Some of my notes:


For this batch of Russian surplus, I started with 20 gr of Russian powder and gradually worked my way up. After each shot I checking barrel for obstruction.
Bullet Puller and Press:
If I were to buy the puller again, I'd probably buy the Hornady cam-lock bullet puller. Problem with the RCBS puller is that when you turn the handle to tighten the collet, you might end up 1. spin the puller inside the quick change sleeve, or 2. spin the quick change sleeve against some locking pin on the press. First case it won't tighten the collet, second case it might damage the press. Hornady's system work by pressing down a cam to lock the collet. I think it would work far better.
See how turning the handle on RCBS puller can cause potential damage to the press:

It also makes it very hard to spin the puller out later on:

That's all. Hope you found this useful or at least enjoyable to read.
7.62x39 Family photo - From left to right:
1. Russian surplus loaded with soft projectile, no crimp
2. Russian surplus loaded with soft projectile, light crimp
3. Gecko 7.62x39 123Gr brass case ($1.3/round!!!)
4. Barnaul 7.62x39 123Gr non-corrosive??
5. Czech surplus came on stripper clips (got an awesome deal, $100 for 570 rounds on stripper clips)
6. Romanian 7.62x39 surplus
