Problems resizing 7.62 x 39 brass

S

stagpanther

New member
I've fired a few hundred cartridges of hand-loads I've done from PPU unprimed brass I bought initially for my PSAK and now for a AR 47.

Problem is, after being once fired it appears that the rim diameter is possibly expanding out somewhat, I can never get it drop into the wilson gauge to headspace check without first "hand-turning" the rim on sandpaper. I know that some of this is probably attributable to the AK's "brutal" extractor, but even some of the cases I used in the AR 47 only show the same issue. These are very mild loads towards the bottom end of the charge ranges.

I'm new to reloading for 7.62 x 39--so I'm wondering if this is "normal" for brass, particular to PPU brass, or should I look for better stuff?
 
Are you sure it's not just an extractor claw burr? Those are common with self-loaders. If you turn the case with one hand while dragging your finger along the rim, do you feel it?

Also, if you have a Wilson case trimmer, you can put those cases in the shell holder for that chambering and turn them backward and close in on them with the trimmer cutter and it will "touch" any bent-back rim area first, starting to shave it and revealing the location of the extractor claw at ejection, which is the likely location of the problem.
 
The outer edge does get chewed up--though there is no obvious and consistent claw mark. A gentle pass over sand paper is working fine, though I am finding a bit of elongation in the neck which needs a bit of trimming. All is good--it's just that it's a bit of extra work.
 
I had a similar problem with my Garand. About 1/2 of my HXP brass reloads would fit my gauge. I worked on it for a couple weeks and found no remedy. I finally posted a question on CMP reloading forum and one member asked it the rounds would chamber. Yep they did! Under further troubleshooting I found the case rim was hitting the OP rod handle on it's way out. Heavier loads resulted in heavier dents, not allowing the round to fir in the gauge. I put the gauge in a drawer about 1,000 rounds ago and have been shooting quite well and troublefree since...
 
I'll probably end up splurging a bit on 7.62 x 39 brass for my AR 47 and keep it separate from my AK brass as it seems the AR 47 is inherently more accurate.
 
Note that some brands are harder in the rim than others. You may just need to find the right one. I bought a bunch of 7.62×39 rounds made by Lapua about a dozen years back at a gun show. They worked out well in my little Russian SKS. I don't own an AK clone to try them in though.


Mikld,

Brass colored op-rod handles are common in the Garand. If you pop for one of the Garand Gear hollow gas cylinder plugs, you'll find they give the brass more time to clear the receiver and drop them a lot closer by. Two birds killed with one stone.
 
My AK is really rough on the rims of my brass, and at first my AR47 was a little rough but not nearly as bad as the AK. Since I went to a heavier buffer in my AR it's recoil is much nicer and it doesn't seem to be as hard on the brass. I wished I could get some steel cased ammo that didn't have any steel in the projectile so I could shoot it at my indoor range. Then I'd shoot my AK a lot more, it is a blast to shoot and even though I've had it since the mid 80's or so, I doubt I've I've put much over 500 rounds through it.
 
Golden Tiger makes really nice ammo, steel cased, copper / lead 124 gr boat tail bullets. The bullets have no steel core, just lead with copper jacket. You can buy it around here for just under $200 for 1000 round box. It's really consistent stuff too, I tested a box of 20 over my chronograph and ended up with a standard deviation of only 13. It even has laquered necks and primers...top quality stuff.
 
I've been pretty impressed with the performance of the budget AR 47 vs the AK clone I have so far, I haven't really explored the hand-load possibilities so that's why I'm looking for the best brass for the job I can find. I'll leave the budget 10 to 20 cents a round stuff for the AK.;)
 
Broke down and ordered a couple of hundred lapua cases--also tossed in a couple of pounds of CFE BLK--curious how this does in a 7.62 x 39 load.
 
Measure before and again after, and then there is the comparator for comparing. The diameter of the rim is said to be .447" and the case diameter is said to be .443" in front of the rim. If you did not check the case in the Wilson case gage before firing measuring after firing is just busy work. I would suggest you turn the case around and place the rim into the case gage first.

It is most difficult to upset a case head/rim with anything but heavy loads.

F. Guffey
 
Extractor burr and ejector dent, they are indication of over gasing and weak recoil spring. It is not ideal for the brass, but there may not be many options when it comes to ak and SKS. I have an idea to improve it on my sks but haven't had time to test it out. In the short term, I just reduce the load.

I understand people like to do that to feel good, but I never use no gauge to check my loaded rounds. I check them with my rifle's chamber. I handload for only one gun. No point trying to meet saami specs.

-TL

Sent from my SM-G930T using Tapatalk
 
Broke down and ordered a couple of hundred lapua cases
Click to expand...

After I got my CZ-527 carbine last fall, I also decided to try reloading for it, and ran into problems trying to find brass. Even mixed unprocessed once-fired stuff was over 30 cents apiece. So, my solution was to buy a case of GECO ammo for 32 cents per round. I essentially got the first firing free (no steel- brass boxer primed cases with a copper/lead fmj), and now have plenty of reloadable brass.
 
stagpanther wrote:
These are very mild loads towards the bottom end of the charge ranges.
Click to expand...

What powder, charge and bullet are you loading?

Can you post pictures?

Do you have a micrometer? Or a set of calipers? Can you measure the diameter of the case just above (heading towards the bullet) the extractor groove?

I am finding a bit of elongation in the neck which needs a bit of trimming.
Click to expand...

How much elongation? Or do you know the length of the cases before you loaded them to know how much they have elongated?
 
Golden Tiger makes really nice ammo, steel cased, copper / lead 124 gr boat tail bullets. The bullets have no steel core, just lead with copper jacket.
Click to expand...

All the places I see it sold say it has a bi-metal jacket. This is code for a steel jacket with thin copper plating. If it had a true copper jacket I'd be more interested in it.

A lot of guys on the web say it's very good stuff, so go ahead and try it out if ya want. I only ever bought one box, and my SKS hated it- couldn't hardly hit a wash tub at 100 yards.
 
Did you measure the bullets? I see .308, .310 and .311 available for this chambering. A 0.003" difference from bullet to bore could well be responsible for poor precision like that.

As to bi-metal jackets, a magnet is your friend. If it attracts the bullet, don't shoot it where steel is not allowed.
 
OK--it's not a big deal--I'm using spent AK fired cases in a new AR chambering and surprise--the AK fired stuff is a bit rough on the edges of the rim. I'm firing 25 to 26.6 grs of RL 7 driving 123 sst's --which is well under the rated max pressure. I'm getting groups in the 1.5 to just above 1 MOA range with my AK loads in my AR 47 so far, and a few virgin cases fired through just the AR 47 don't have the issues the spent AK stuff does. I think I'm good as long as I keep the brass for the two separate.

Yes--.310 bullets BTW

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