Issue with LEE C312-155-2R in 7.62x39

[am44mag]

I'm having issues getting my 7.62x39 AR to work with cast bullets. The mold I've been using is a LEE C312-155-2R. I am powder coating these boolits, and am also using a gas check. I am seating so that the OAL is 2.20".

I originally had them sized to 0.3125", but that was too fat. The bullet would get pulled out of the case and would just be left lodged in the barrel. So after knocking the bullet out of the barrel, I slugged the barrel and did a cast of the chamber. The barrel is at 0.311", and the throat is at 0.312". I figured sizing to 0.311" would let the rounds feed smoothly, but that didn't end up being the case. They definitely fed better, but I still had some rounds not chamber fully. After inspecting some of the rounds, I noticed that the powdercoat had been more or less shaved about 1/2 to 3/4 the length of the exposed part of the boolit. I measured this just to see what it said, and they ranged from 0.309" - 0.310".

At this point, I'm not sure what the problem is. Maybe I got the powder coat too thick towards the front half of the bullet? Maybe it's just too fat in general? I'm tempted to buy a different mold to see if that solves the problem, but I don't want to spend the money unless I have to. The one I was looking at is the 312-145 Elvis from Arsenal molds. I'm not sure if it would be any different though. Any suggestions?

http://arsenalmolds.com/index.php?route=product/product&product_id=192

[Forrest r]

Your oal is too long.

[RU shooter]

If the rifling marks are on the fore part/ nose of the bullet sizing smaller ain't gonna do anything for you you'll need to seat it deeper

[Larry Gibson]

The PC is making the nose too thick. That bullet is designed to "fit" as a naked lubed bullet. The C309-160-R would be the better choice for PC'd bullets in your AR.

[Kraschenbirn]

+1 on what Larry said. Best remedy for that particular boolit design is probably to nose-size but that's time-consuming and can be a PITA. The Arsenal 'Elvis' mold, or similar, might be a better solution of you're planning to cast and size in sufficient quantity to feed and autoloader. I've have a couple of Jared's molds an can attest to their quality.

Bill

[am44mag]

This is what I was talking about. Shaved might have the wrong word, it's probably more accurate to say sized down. The powdercoat is still on the boolit, just sized down a bit. I played around with the OAL, it made no difference. I'll try some uncoated bullets and see how that goes. I'm thinking you guys are right about the powdercoat on the nose being the issue. I was kinda dead set on powdercoating my rifle boolits, it just makes everything a little easier for me and I enjoy the process. I might have to pick up that 160gr LEE and see how it does.

Thanks fellas. I'll report back when I know something. I won't be able to shoot or cast boolits until Monday or Tuesday though.

https://uploads.tapatalk-cdn.com/20200202/0f03c79ceff49aa789d27c0f4293c0d9.jpg

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[Texas by God]

These work great in my AR 7.62x39. YMMV.https://uploads.tapatalk-cdn.com/20200202/bfd3c6575d566807bf0dbed6a530b5ac.jpg

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[am44mag]

So I cast some more boolits, and loaded up a couple of dummy rounds. They both fed, but had circular cuts on them near the nose.

https://uploads.tapatalk-cdn.com/20200205/6f329d5d135295e0a5d3dc0f63208de8.jpg

So I modified a fired case so that the boolit could move with only a little bit of resistance and checked to see what OAL the gun wanted. Roughly 1.160". I checked it twice.

https://uploads.tapatalk-cdn.com/20200205/a6df525bf35053e6ce5a79ca43fd98d7.jpg

https://uploads.tapatalk-cdn.com/20200205/1880a1fbaa1fcf8cd31f15976b047e8f.jpg

Does that seem like a ok length to seat the boolit to? It seems a little deep to me.

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[RU shooter]

I'd run with that

[Muddydogs]

You have learned the lesson on your own that I am always harping on whenever someone spouts off book OAL numbers. The book OAL number means very little since your probably not using the same rifle or test barrel they used to develop the load and even if you are using the same rifle there is no guarantee that your chamber is exactly the same as the test one. You did the right thing by measuring your chamber and figuring out the OAL that works for you, now work up the powder load with that seating depth and you will be good to go.
Did you also notice that in your last picture that the case mouth is at the bullet crimp groove? I would fine tune the seating depth to make sure the case mouth is far enough into the crimp groove for proper crimping if you plan to crimp. Hard to tell from the pic if any adjustment is needed.

[am44mag]

It was in the right place to crimp into the crimp groove.

I loaded 15 rounds with the boolits set to 1.156", and all but 4 fed reliably. I tried seating those 4 deeper (as deep as 1.425"), and it made no difference on those. I'm not sure why those 4 would behave differently than the other 11.

I went ahead and ordered that 312-145 Elvis mold from Arsenal, so hopefully that will be a better boolit for this gun. I haven't given up on the LEE yet, but I'm not sure what else I could do to get it to work.

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[MrHarmless]

Those bullets will work, but the ogive (~2R) is really short on them compared to "normal" bullets for the 7.62 x 39. You do have to seat them deep. I use them in 300 blackout for supers, and I have to seat them to 2.02 ish so they don't engage the rifling when they chamber. That happens to be around the crimp groove on that bullet, but most manuals around that weight (mine come out to about 170 gr with a gas check) cite a OAL of 2.2! Gotta start the load low and work up for sure.

[gwpercle]

I was going to suggest trying out a few loads with the boolits gas checked and lubed with conventional lube....but I see you have already ordered a new mould .

It would seem that if boolits are too large after powder coating maybe trying them without the powder coating would help.
Kind of like what we used to do before powder coating took over ... but heck that's so old school and stone age...no body does that anymore.
Gary

[rockshooter]

I have been happy with the NOE 311-150-SP-L1 which is the equivalent of the 311314. The nose portion is small enough (.302) that powder coat does not interfere with chambering.
Loren

[FLINTNFIRE]

I am going to try the 311-175 from arsenal in my blackout , just put in notes what you want diameter to be , I tried a lee 30 caliber mold in my blackout and after powder coating it is to thick and it is either size to fit or try another mold and since I wanted heavier anyway, I know you are doing the 7.62x39 and with getting a custom mold you can play with a wider selection good luck

[leadman]

I ran into a similar problem with a couple of my rifles with loads I used repeatedly. Finally found a very hard carbon ring in from of the neck of the chamber with my borescope. Cleaned it out and no more problems. I Hi-Tek coat my bullets and I think the carbon might be from the coating. Never had it with wax based lubed bullets.

[lotech]

I'm having issues getting my 7.62x39 AR to work with cast bullets. The mold I've been using is a LEE C312-155-2R. I am powder coating these boolits, and am also using a gas check. I am seating so that the OAL is 2.20".

I originally had them sized to 0.3125", but that was too fat. The bullet would get pulled out of the case and would just be left lodged in the barrel. So after knocking the bullet out of the barrel, I slugged the barrel and did a cast of the chamber. The barrel is at 0.311", and the throat is at 0.312". I figured sizing to 0.311" would let the rounds feed smoothly, but that didn't end up being the case. They definitely fed better, but I still had some rounds not chamber fully. After inspecting some of the rounds, I noticed that the powdercoat had been more or less shaved about 1/2 to 3/4 the length of the exposed part of the boolit. I measured this just to see what it said, and they ranged from 0.309" - 0.310".

At this point, I'm not sure what the problem is. Maybe I got the powder coat too thick towards the front half of the bullet? Maybe it's just too fat in general? I'm tempted to buy a different mold to see if that solves the problem, but I don't want to spend the money unless I have to. The one I was looking at is the 312-145 Elvis from Arsenal molds. I'm not sure if it would be any different though. Any suggestions?

http://arsenalmolds.com/index.php?route=product/product&product_id=192

I think the bullet you describe is a copy of the NEI 311.155GC designed by C. E. Harris at least thirty years ago. It was designed for the 7.62x39 cartridge. I don't know how close the specs on the Lee version are in comparison with the original design, but the NEI bullet has a pretty fat nose to fit SKS chamber throats as I recall. I have the NEI mould, but no bullets on hand to measure.

My notes, coincidentally, show an OAL of 2.20" when loaded for the chamber of a Ruger bolt-action 7.62x39. I sized to .311" for the Ruger (and I think about .313" for the two SKSs I once had). I would not hesitate to seat your bullet deeper for your AR, but would experiment to where you get ever so slight (or even a hair less) bullet engraving when a cartridge is chambered.

I haven't used my NEI mould in years as I prefer a heavier bullet, but my notes indicate the bullet was accurate and your Lee version may also shoot very well. Good luck-

[Larry Gibson]

Have you slugged the bore of the AR? If it is a .308 then getting a mould with a .300+ nose may not help. [not sure what the nose of the Elvis bullet is?] If the bore/ Groove is .308 then a standard 30 cal bullet would be better.

[am44mag]

Have you slugged the bore of the AR? If it is a .308 then getting a mould with a .300+ nose may not help. [not sure what the nose of the Elvis bullet is?] If the bore/ Groove is .308 then a standard 30 cal bullet would be better.The barrel is 0.311, the throat is 0.312.

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[am44mag]

Look at what showed up today. :D

https://uploads.tapatalk-cdn.com/20200220/74f62ee7ee6e43f8654215e1f733f908.jpg

https://uploads.tapatalk-cdn.com/20200220/d90e18f9240004ecaeadf9d44af9e478.jpg

Hopefully it works a little bit better. If not, I have a few other guns that might like it.

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[am44mag]

These are looking promising. The base casts at 0.314", and the nose is at .308". I've got about 200 of them cast, so I'll see about powder coating and loading a handful of them tomorrow and see how that goes. I won't be able to shoot until next week though.

https://uploads.tapatalk-cdn.com/20200221/40184d3e8d6bf122da74ded0d8b9394a.jpg

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[FLINTNFIRE]

My 311 mold cut to 308 and powder coated is fitting fine in my 300 blackout , I had it cut so I could skip sizing if possible now to shoot a string of 3 different loadings and see results , wish you luck and from size of your bullet and throat you are sizing them down , when I get the new lee press I will revisit my other mold that was to fat it was ending up at 312 and would not chamber .

[am44mag]

Well fellas, I never did find a mold that gun would shoot. I'd really like to be able to shoot cast in it, especially with reloading components like bullets getting harder to find. I have a decent stock of them right now, but I'd be much happier being able to make my own.

Do you think I should have the throat reamed? How much would that cost, and who could I send it to to do that?