View Full Version : 7.62x39 steel cases to boxer success

08-23-2015, 07:31 PM
It ended up being pretty easy and I doubt I am the first to do this. With the piles of steel Russian cases littering our range I had to find a use for them.

the process-

1- fill case with water and use a 1/4" Craftsman extension screw driver head socket to hydraulically extract primer.

2-put case on a rod and use a punch to beat down the anvil flat,The twin flash holes are still there but the displaced them about half sized.

3- add three stakes to primer pocket and with chisel ground down make the new primer fit tight. (Berdan primers are a bit bigger than boxer.

4- put case in a fl die(or Wilson type holder) and drill out the primer hole on a drill press. Cut hole a bit deeper with a carbide primer pocket tool

5- size,prime and load as usual.

I used a load of 14.5 of 2400 and the lee Ed Harris bullet as my test.I'm not sure how full loads would work.

I ran 40 of these with no issues in a WASR 10 Ak47.Fires cases looked just fine

Its not a fast process but it works. I now have over 1500 of the cases collected from local ranges.A machinist buddy is
coming up with a better set up to do the conversion. I hope to have 1000-2000 cast loads with aluminum CG;s and reclaimed lead loaded and ready to plink with as a winter project. I figure I can load them for much less than $100 per 1000.

pics to follow

08-23-2015, 07:54 PM





08-23-2015, 07:59 PM
The fired de primed case.


08-25-2015, 10:33 AM
No gas leakage around the primer? Seems like it would to me.


08-25-2015, 11:36 AM
I have done this with steel 54r cases. Superglue around the primer once it is put in is helpful, and seals relatively well.

08-25-2015, 11:46 AM
watch the flash hole is centered well or your may break a depriming pin

08-26-2015, 02:15 PM
No major leakage to speak of ,but the load is not full. Yes the primer hole location is critical.But I’m not going to reload them.

08-27-2015, 01:09 AM
Doesn't the built in anvil create a corresponding dimple inside the case. This dimple is a perfect drill guide. Use a long 1/4 shank center drill to drill the center flash hole from the inside out.

Then the primer pocket uniformer cleans up the rest. A little deburring and your done and have a perfectly centered flash hole.

Maybe the steel cases don't have the dimple. I know the brass 54R cases do. I made a kit to do what you are doing but didn't like the loose (larger) primer pockets then found a bunch of boxer primed 54R brass and abandoned the idea.

Instead of the primer pocket uniformer, which I think is a better way, I used a 7/32 end mill. My kit is pretty good. I was pretty proud until the boxer primers just fell right in. Lol

That's what you get when you have a brain storm but not all the facts. I was at the shop and had no way of knowing what diameter the boxer primers were. I just simply never had a reason to measure one.


08-27-2015, 09:14 AM
I think if I drill out the anvil then uniform it the flash hole would be left too large and thin in that area .with the existing twin berdan holes it would have more leekage as more gas would be ecpaping to the back?.by flattening the anvil the holes are nearly covered and metal is forced down to make the primer hole area solid..again just done out of boredom.

08-29-2015, 08:38 PM
Years ago I read that someone had modified the primer pocket of Berdan cases with a brass tube, cut to length, and reamed to accept a large rifle primer. I can't remember if the sleeve was superglued or soldered. It's been over 40 years since I read this. Sorry I can't give more information.

08-30-2015, 01:47 AM
I read where a guy used pieces of copper tubing pressed in the large primer pockets then used the uniformer for small primers to cut it to size. I would be hesitant to heat the head of a cartridge case to solder the piece in place. This area needs to remain work hardened to take the pressure.

08-30-2015, 09:05 AM
What about drilling the case from the inside and using the berdan primer anvil as the way to center?

08-30-2015, 04:29 PM
What about drilling the case from the inside and using the berdan primer anvil as the way to center?

you would have to flatten the anvil after and re drill Drilling from the primer side is aesy

09-06-2015, 04:14 PM
How about putting the case on a mandrel and a ball bearing in the primer hole and smacking it. This is the way we close up holes that go big when being reamed.

In this case you are looking to get the hole closed up to about .211 in order to hold the primer. Use about a 1/2" ball so the majority of the force forms the hole inward.

What this does is roughly the same as a full circle crimp on a primer except you do it before you press the primer in.

Also if you chuck the case in a lathe collet it is not real hard to drill the hole in the center of the pocket using a center drill even before the pocket has been flattened.


09-06-2015, 04:25 PM
I have a bunch of berdan brass stuff I might try this out on. Thanks for the tip

09-07-2015, 06:31 PM
Larry Gibson wrote a report years ago on his process, albeit to brass cases . Good information in his report. http://castboolits.gunloads.com/showthread.php?143958-Converting-Berdan-primer-pockets-to-Boxer

I use his process to convert .308 Berdan cases because they are plentiful. I use my brother's lathe to drill out the primer pocket. I've loaded some cases a half dozen times or so, cast loads only though.

I realise I can buy once fired for cheap but let's face it, there is nothing on TV so I just tinker.

09-07-2015, 07:26 PM
Larry's method works fairly well with 7.63x39 steel cases. You drill out the primer leaving a ring of primer brass in the pocket and then use a swager to swage the brass ring to LPP size. I get about a 70% success rate on Tulammo steel cases.

09-08-2015, 12:40 AM
Lots of other good ideas. I like not having to use SR primers.I have quite a few CCI 350 primers I got cheap I'm using up.

09-10-2015, 05:02 PM
What about drilling the case from the inside and using the berdan primer anvil as the way to center?

Already covered that in post #8. I found my fixture and kit I made today. I stated in my last post to use a 1/4 center drill from the inside. This was a mistake, simply bad memory. The flash hole would be way too big.

However I did use the dimple inside the case to accurately locate and drill the new flash hole. I would then clean up the inside of the primer pocket with a 3/16" end mill. I wasn't worried about over pressurizing the primer with the extra vents because I intended to use the casings for sub-sonic cast loads.

What stopped me was the fact that the "brass" berdan primed cases I had actually had the larger berdan pockets the ones that are very close to 1/4".


09-19-2015, 08:34 PM
For moderate loads, I just drill out the pocket for a shotshell primer -- depending on caliber/ weapon/ case sometimes requires spotfacing a
relief for the primer flange -

10-10-2015, 09:28 AM
+1 on the shotgun primer. I haven't tried full house loads but normal cast boolit loads work well. Once drilled and counter sunk for the primer flange they reload over and over rather easily. Made a couple of punches for depriming and priming the whack-a-mole style. I drilled out a piece of pipe that just fits over the case and up against the rim, set a primer on something hard and drive the case onto the primer.

10-21-2015, 05:17 PM
Have friend who works at indoor range and gives me all his steel 7.62x39 cases. I built a hydraulic air over water device using a sizing die with plumbing system that allows me to fill case with cooling fluid use in machining equipment, insert into die then press a foot switch to send 180 psi at as many cfm can get through top of sizing die. Have five gallon bucket to catch most fluid to recycle. Of course this is an in the shop, not u ouse type operation. Cheapest press could find along with a cheap sizing die and investment is not much if you have a shop compressor.

Once decapping is complete dry cases quickly but using machinists milk instead of water really helps mitigate rusting issues. Buy Milwaukee Hawg Wash and mix with water at local machine supply. Once decapping have two options. Luckily for me purchased Berdan primers in bulk for years. When issues first showed up due to trade embargo with Russia supplier told me he would not be able to get the shorter x39 primers for some time so purchased his last 25,000. Suggest if can find Berdan primers, buy them and use proper size.

The best work around I have found is to carefully remove anvil from large rifle primers and seat as normal. Then turn cases neck down and go down the line putting a drop of thin superglue at edge of primer pocket and it will wick down and around the primer and hold it firm. Saves a bunch of case modifying. If rather modify, use a power case prep center with large rifle primer pocket uniforming tool to remove anvil and I made a tool using a drill bit set into a pilot to drill my boxer conversion hole then back to superglue and large rifle primers without removing anvil. Hopefully my short Berdan stock will hold out till find more. Just way too easy to use the correct primer.

Load all of mine using 160 grain Lee bullet with home brew gas checks and sized to .312. Load either Reloader 7 or AA2230 behind the boolit and at 75 yards my cast loads group better than milsurp, are darn close to free as have less than a dime each into each loaded round. They hold up and group well as far as shoot any of my x39 combloc rifles. The AA2230 goes farther than Reloader 7 and groups as well. Have run several thousand through my tuned SKS range rifle and run perfectly. If use boxer primers without modifying case remember to remove anvil from primer or if it lines up with flash holes may have a dud.

12-08-2015, 04:50 PM
For the effort involved wouldn't repriming with Tulammo KV24-N primers be a lot more effective? I understand the cost savings of reloading the steel cases but adding $20 to each thousand rounds is worth the time saved not having to do the boxer conversion I would think. DAG ammo sells them, among others.

02-06-2016, 11:32 PM
GONRA is impressed with all the novel techniques / methods
dreamed up for "primer pocket modification".
Just make sure you guys wear robust safety glasses!

Remember some firearms REALLY don't like primer leaks.
WW I era 9mm Steyr pistols can then have the extractor blow off
releasing the firing pin to shoot out into your eye.

A pause for the COZ
02-07-2016, 12:13 AM
Couple things I have tried.
I hate the water method to deprime so I came up with an alternative.
I took an allen wrench and ground a point onto it. Mainly on one side so you can leaver it in the pocket after you puncture the primer. The Allen wrench works because it is made from a hard steel and wont bend the tip.




Obviously Berdan primers would be preferable. If you cant find any, just remove the anvil from a boxer primer. use the berdan anvil.
Place them in the primer pocket and put in a drop of Super Glue.
Works great and have done full power loads. Can be reloaded again.



Plate plinker
02-11-2016, 07:39 PM
Creative guys. You all must have a lot of time on your hands.

02-12-2016, 01:11 AM
Who can honestly say they don't have spare time ? Fight the urge to sit infront of the t.v and do something that others won't.

09-28-2016, 01:22 AM
I have the luxury of a small lathe, and after many different approaches, I came up with a 4 step process for converting them to boxer primed.
1) I use a 1/8" carbide end mill in the drill bit chuck and remove the center of the old Berdan primer and machine down the Berdan anvil .030".
2) I use a 5/64" drill and carefully drill a center hole between the two Berdan holes.
3) I use a Lyman primer reamer to optimize and true the remaining primer hole just enough to allow it to be expanded by the RCBS primer pocket swager tool in the press.
4) I use the RCBS primer pocket swager tool to form the primer pocket to fit a small rifle primer.

After a lot of trial and error, I have gotten the small rifle primers to press perfectly into the primer hole and feels just like factory brass with my Lee primer tool. The final product is somewhat subjective, but you get better as you go along.

This group was shot with my Mini 30 at 200 yards with these converted cases, but I confess they were Speer 150 gr flat base jacketed spitzer bullets http://castboolits.gunloads.com/images/icons/icon4.png with 27 gr. H322. This was done for proof of concept, and I have a bunch of Lee 155 bullets cast up to try next, probably in my SKS, or my custom Mauser 95 that was converted to this slick little cartridge. Wolf 154 gr. soft points were also respectable, but not as good at about 3" at the same range (LRF)

Just a side note...earlier in my experimentation, I used a tiny drop of red Locktite if I had any doubts about the primer fit, but have pretty much abandoned the method since I figured out how to get the tight fit.

09-28-2016, 01:48 AM
Jlucas, this is fantastic. well done !

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09-29-2016, 04:03 AM
Once upon a time a friend had a batch of .45 ACP cases that included about 50 steel US made 1943 cases.
The steel was softer than brass and I had to toss about 25 of the cases. I loaded the rest and we left them at the range after picking up all the brass.

09-29-2016, 11:30 AM
I tried this system. US made primers were a bit loose. Sealed it with superglue, old nail polish (old one's my wife was not using) both did very well. Then I got a hold of some primers that were made by Sellier & Bellot, those one came in tight. Did have to use any primer sealant.

09-29-2016, 11:34 AM
O Really ! Thanks a bunch for the tip !!!!

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