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View Full Version : 7.62x39, What am I doing wrong?



dmclark523
04-10-2013, 12:12 PM
I'm casting currently for my AK-47, just to do some testing on it, and how it reacts to cast boolits. I've cast a bunch of Lee 312-160, which is compatible with gas checks. I slugged my barrel, came out to .3135, roughly.
I cast the boolits, thinking that most of my Lee molds drop a tad bigger than advertised.
I bought a .314 Lee Sizing kit, and TL'd a test batch of 20. After, I applied .30 Cal gas checks and went to size. I had almost no resistance in the sizing die, and it didn't crimp my gas checks as I had hoped.

I was under the impression that AK or SKS were supposed to be about .311. Mine is a Romanian WASR-10.

Do I need to buy a custom mold, or should I try and load these anyway. The gas checks are pushed on, but it wouldn't take more than a pair of small pliers to pry them off.


EDIT: Reslugged several times and came up with .3125, and rechecked some boolits, and they dropped at .313.

runfiverun
04-10-2013, 12:25 PM
now you know why we measure barrels instead of going by what we think.
and what do the boolits themselves measure?
if they are 3135 or so i'd try a couple.
you can open the mold a little bit quite easily, change alloy, or just work on the gas check shank some.

dmclark523
04-10-2013, 12:30 PM
Well, to be completely honest, I didn't just buy and hope for the best. I got the mold from someone for free who was returning a favor.

The boolits fall at .313, give or take. How would I go about 'opening my mold up'? Maybe there is a sticky or another thread detailing this
that you could offer? Thanks

rintinglen
04-10-2013, 12:31 PM
Your Lee mold may not be casting Large enough. Welcome to the world of milsurps, where nominal bore diameter is purely a ballpark figure. You can try "beagling" the mold, and making your boolits larger, or else you can quickly call Al at NOE molds and see if he has a 316-155 mold left from the recent group buy. Otherwise, Tom at Accurate Molds can fix you up. Check the stickies for info on "beagl-ing." That may be the most cost effective method.
A .311 boolit will almost certainly lead badly in your .314 barrel. You need to go bigger.

leadman
04-10-2013, 12:53 PM
A Lee mold can be easily opened up a .001" by using some kitchen cleanser like Comet on a boolit that was cast in the same cavity. Drill a small hole centered in the base of the boolit and install a wood or drywall screw. Make a paste of the cleanser and water and smear it on the boolit driving band area. Keep it off the nose and gas check shank unless these need to be larger. Spin the boolit in the cavity with a cordless screwdriver or drill. Check often by cleaning and then casting a sample boolit.

Most of the foreign guns that fire the 7.62X39 that I have slugged have dimensions similar to yours, including my SKS.

badbob454
04-10-2013, 01:27 PM
my russiann sks loves the 314-175 saeco clone Noe made

dmclark523
04-10-2013, 03:05 PM
I've sent some emails out, and we'll see what happens.

Meanwhile, as edited in my first post, I re-slugged 3 more times to be safe, and came out with .3125. Not sure why the discrepancy before.

Also, bullets, after checking again, checked .313 pretty much on the dot. I'm nervous about shooting them though... I don't want to be dealing with a leaded barrel all day...

historicfirearms
04-10-2013, 03:28 PM
My WASR groove diameter is .3125", M92 is .313, Romanian G .313, Mak-90 is .3145. So you measurement sounds reasonable. I'd try shooting them at .313, they might be ok. Leading isn't that big of a deal to remove if you only shoot a few of them.

Want a shocker, measure the inside mouth of some of your fired brass. Most of the chambers are VERY generous. Probably why AK's with .310 Jwords have a reputation for poor accuracy.

If you can get the 315-155 NOE mold, do it. It's a great boolit for the AK.

dmclark523
04-10-2013, 04:48 PM
My WASR groove diameter is .3125", M92 is .313, Romanian G .313, Mak-90 is .3145. So you measurement sounds reasonable. I'd try shooting them at .313, they might be ok. Leading isn't that big of a deal to remove if you only shoot a few of them.

Want a shocker, measure the inside mouth of some of your fired brass. Most of the chambers are VERY generous. Probably why AK's with .310 Jwords have a reputation for poor accuracy.

If you can get the 315-155 NOE mold, do it. It's a great boolit for the AK.

What do you size that at?