Cast boolits + AK-47 =

[chris in va]

Jam. My gun locked up today due to lead buildup in the gas block. I guess it's just not going to work for the AK.

40 rounds the other day, 40 today and it stuck solid. I had to jam the handle on the table for it to unlock.

[nicholst55]

I don't know anything about the boolits you were using, but if it works in an M1 Garand, M1A, SKS and other gas guns - without leading up the gas system, I would have to believe it can be made to work in an AK.

In my experience, the AK and SKS are both W-A-Y over-gassed, to insure operation in all climates and temperatures, with crappy, 3rd-world ammo. That doubtless is not an asset when working with cast boolits. There used to be a pictorial explanation on this forum about reducing the gas pressure in the SKS gas system; the same theory should apply to the AK. Let me see if I can find it.

[Piedmont]

Yeah, I'm wondering about your loads--lubricant, sizing diameter, etc. If you are shooting undersized or inadequately lubed bullets they will lead.

[chris in va]

Lee 312-155-2r
Water dropped
JPW/Mineral spirits
Sized to 311 with gas check

No leading apparent in the rifling, not sure what happened with the gas block. The picture was taken after I scraped off most of the lead ring.

[RU shooter]

I've shot quite a few through mine in the past and never seen that happen????

[chris in va]

How many did you shoot through it at a time before cleaning?

[RU shooter]

20-50 at a session but I honestly never seriously cleaned the weapon where yours is leading just wiped off the end of the gas piston and a quick swab with a oiled patch in the gas chamber and never got any "real " lead build up on either how fast are you firing off those rds.? Not bump firing or anything like that are ya.Maybe try a better lube and see what happens?

[chris in va]

Not bump firing, although I would love to.

Just one every second or so. I'll try doubling up my JPW and see if that helps.

[Piedmont]

The smallest 7.62x39 I have slugged (out of five) was .3115 in the grooves. I wouldn't use a .311 bullet even in that one. I would also use regular lube in the grooves.

You didn't mention the load (powder charge) or what your rifle slugs but I'm guessing your bullet is too small.

[truckmsl]

Rapid firing an AK with cast will always load up the gas block in my experience. Slow things down, and not so much.

[82nd airborne]

I dont get issues in the AK with the gas system leading up at all, however, there are rough sections in my bore that pic up a little lead. Then again, I dont shoot really hot loads through mine, as I use it mainly with subsonic ammo, since the AK surprisingly makes a decent, quiet, straight pull. I also do shoot the lee 165gr TL GC boolit through it at around 1900-2000fps sometimes. I dont shoot it that much though, as I prefer the AR over the ak.

[Ole]

.311" is way small for that bullet.

Try sizing it .314 and see if the leading problem disappears.

I use the .314" sizer in my SKS just to seat the gas checks.

[Black Wolf]

I agree with Ole - none of my Foreign Aks slugged under .312". I use a .314" bullet. It may be the .311" is causing some gas cutting and being blown up into the gas port.

[x101airborne]

Maybe try borrowing an 8mm mold. I would water quench them and size them within 24 hrs. Then you could try any diamater you want. It definately sounds like your boolits are gas cutting, though

[JIMinPHX]

.311" is way small for that bullet.

+1 on that. I size that caliber to at least .3125" minimum. You are probably getting gas cutting before the boolit gets anywhere near the gas port & that pre-liquified lead is probably causing your problem. I've never seen a Russian gas system gum up like that from lead boolits. The Russian guns tend to be very forgiving. The AK system has even more clearance built into it than the Siminov system on the SKS.

Some other things that you might want to try are lube related. After a good cleaning, warm up the area where you have leading problems to around 250F & apply some bullplate lube. This worked well for me on the gas piston of an SKS that used to foul a little bit on the crown. A lot of people lube the gas system with a lite coat of ATF. You also might want to try a different boolit lube, just to see what difference it makes. Carnuba Red and Lyman Super Moly lube are 2 that have always given me 100% lube performance. The moly is a bit of a mess to work with, but flows well at room temperature. The CR needs to warm up a little to flow well, but is great as an all around lube.

[truckmsl]

JimMinPHX,

Even with a .314 boolit, gas checked, with carnuba red and 15 grains of 2400, which is not a hot load, I get gas port fouling if I shoot rapidly enough to heat up the barrel much. Are you able to avoid gas port fouling regardless of rate of fire?

[JIMinPHX]

I'm not a lead sprayer. I treat my rifles like rifles & not like lead pumps. That could be the difference. Alloy might make a difference too. 15 grains of 2400 gives me good results. I get a little lead fouling in a ring at the start of the piston tube & a little on the piston crown, but not a lot.

[res45]

In my SKS rifles the bore slugged .312, I use the Lee .312 TL 160 gr. shot as cast and water quenched.

Bullet drops at .313 I TL once in Lee Alox/JPW mix no MS,gas check is applied with the Lee .314 push through sizer then TL once more before loading.

I shoot slow fire get great accuracy and have not leading issues other than a little lead on the gas piston face which cleans off easily.

[truckmsl]

JIMinPHX,

No need to preach - I'm not a lead sprayer either, and enjoy surprising accuracy from my AK with cast at 200 yards. I have seen gas port lead fouling occur, and your previous post suggested that was not normal. I believe it is normal when the rate of fire is too rapid.

[JIMinPHX]

I didn't mean to preach. I'm sorry if it sounded that way.

Some fouling is normal. Rapid fire will probably increase the amount of fouling to some degree. I'm not sure how much because I don't do it. Soft alloys, poor boolit fit, a gas port that just happens to enter the wrong part of the rifling, a very hot burning powder, & rough metal surfaces will probably make the problem worse. Good cleaning practices, a little polishing, & proper lubrication will probably help to minimize the problem.

Cast boolits are a good choice in many applications for a number of reasons. They are not the best choice in every application. Prolonged rapid fire in a semi auto may require a shooter to rethink his ammo selection. Fouling is not the only issue. I've found that Greek surplus ammo tends to heat up a Garand barrel a lot faster than other types of ammo that I have fired. For prolonged rapid fire in an -06 of any description, I would avoid the Greek stuff because the powder seems to burn too hot.