Okay, I've read all the 308 conversion threads and MG47 threads over and over. I still have a couple months until I can get back in the shop, but here is what I am planning:
A Belt-fed, AK out of a Yugo RPK kit in .308, using the original finned RPK barrel just reaming the chamber.
I have got SS's MG-47 plans, an RPK I cut to 19" to make a carbine that I am not particulagly pleased with, an MG3 FT and TC on order, a good source for 308, and the desire to use disentigrating links.
I need a chamber reamer and a spare 1,000 hours. The question is, and I have found some folks that WANTED to do it, but what results have you had with reaming out the x39 chambers to .308. I know the whole .308 vs .311 issue and I am okay with that for a "proof of concept" build. I got the RPK kit a year ago with a shot out front couple of inches anyway so it is a good candidate.
Thoughts? Has anyone tried this yet?
If you are any good at reaming barrels, and promise to return a reamer in the condition it was lent, I have an extra 308 reamer i'll loan you for shipping costs.
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Well, thanks for the offer, but I have yet to ream a chamber, so I would have to either send out the barrel, or abide by the "you break it, you buy it" policy (which I most certainly would). Either way, I am looking at late December at the soonest to get started. What brand are you using and what do you think of them?
I have used several reamers from different manufacturers, and haven't had a really bad one yet. Because of my lack of negative experiences in chambering barrels I cannot really say that i dislike any one brand.
When it comes time to do it, if you decide to have it done by somebody else, give me a shout.
Thanks, I will probbably take you up on that offer. As for the rest of the project, I see very little that will have to change from SS's original design. I'llbe doing it with spade grips (it's a CA thing) I am thinking:
1. stronger return spring and bigger ejection port
2. venting the gas tube to slow the bolt due to the impulse from the higher chamber pressure/ more gas.
3. position feedtray a little furthur back (I was thinking about 12mm) from the breach to give the round more distance to align and not have as sharp an angle (am I off on this one??)
4. thicker steel for reciever and after it works, weld it all up so if something catastrophic happens the path of least resistance is up through the feed tray and top cover.
FOR THE RECORD, I'll say that a .308 barrel should be used. Not sure how well that will run , but others with more experience in that may have a different opinion. The effects on accuracy are questionable.
Originally Posted by MustangO3
Another "FOR THE RECORD" - my .308 build shoots custom loads that are loaded primarily for accuracy. These loads are lighter than factory surplus ammo. I would say that all of this surplus ammo people are buying would be too hot for my build, and I would not recommend it for other builds. Did the Yugo 308 builds have the same bolt? Yes. Is this a Yugo RPK? That would be the best place to start because visually the bolts are identical.
From my own personal experience with my .308 conversion, I would consider the AK gas port too large - you'll beat the rifle to hell and back! Therefore, you could either
a) drill more vent holes on the gas tube
b) drill a smaller barrel, more in the size like on a FAL gas port.
"B" ovbiously assumes a new barrel, which I think will be better. I would not recommend plugging, then re-drilling the gas port. The gas port plug would be nothing more than a threaded insert, and would need to either be welded on, or a tapered fit at the outside edge like a cut-down bolt head, so that it would not "walk" down into the barrel and block it. That would be bad.
A tapered fit at the outside edge would assume you would cut a notch into the barrel for this extra material to reside, so that you could actually reinstall the gas port back onto the barrel.
Drilling more vent holes in the gas tube seems to be a far easier ordeal. You'll obviously be bleeding a great deal of gas away from its intended job - pushing the bullet down the barrel - so performance may be lackluster.
If you leave the port as-is and "simply" rechamber, if it works, it will not work well because the sheer amount of recoil energy will literally beat the gun apart. The rivets on the rear stock tang/trunion will be peened out from the excess force applied against them. The axis pins may also peen egg-shaped due to the excess force of the bolt carrier when cycling the action.
On my .308 conversion build, I cut 4 extra gas ports on my gas tube and that toned it down enough to work.
Moral of the story -
1. Pookie recommends a .308 barrel for .308 bullets.
2. "IF YOU MUST" - Pookie recommends drilling extra gas ports in the gas tube.
3. Welds have no place on an AK receiver. Use a milled receiver if you want extra strength. Or reinforcement bars like HK did on their short-lived HK-21 model.
4. Pookie recommends caution - you are pushing really high pressures with a .308 and I would not want to see you blow parts of the kit into your face!!!
THANKS A LOT FOR THE INPUT!
That is what I am thinking about and discussing here before I get started.
Yes, it is a Yugo "finned" RPK kit with the "bigger" bolt and bulged trunion.
I planned on doing exactly what you are saying on the ported gas tube. I was actually thinking of drilling several holes in it (what is the hole setup you used to get yours finctioning properly?) and then sleeving the gas tube with a sleeve that slid over the ports to be adjustable so i can start with the most holes and least gas inpulse, then slide the sleeve over it to get to the right combination of gas venting and impulse to operate the gun.
As for the chamber reaming, that is why I am looking for someone who has done it. I heard a few folks mentioning doing it, but I couldn't find the updates (that might be a bad sign) I REALLY want to use that big, fat Yugo finned RPK barrel though. it is one of the coolest looking barrels out there.
And on the ammo, yes, I shooot my own reloads that I load light anyway. Still in the research/brainstorming phase though. Thanks again for any input.
It is using one of the YUGO RPK kits like this one with the big heavy barrel. (Photo shamelessly stolen from a gunbroker ad, but I bought two of these from this guy, so I doubt he'll mind).
The receiver on the MG47ES is 1/8" thick v.s. .039 on a standard AK receiver. I don't think you need to go any thicker than 1/8". G3 receivers are no where that thick although they are deeper. My ES with a RPK front end weighs about 14 lbs. with a 1/8" thick receiver.
Thanks, I had re-thought that after my original post, but never edited it. I think once I get it going I will replace most of the screws with rivets/ weld to get the strongest reciever possible. I'll still keep some as screws for tweaking/ replacement etc. My whole thought process is ensuring that if there is a chatostrophic failure it goes up, through the top cover. The only ones I have seen personally were on M2 and due to headspace issues and that shouldn't be a problem with this. Really, I can't see any way, if you do it right, that this could be any more prone to disaster than a standard 308 SA rifle.
I am still looking for someone that has successfully re-chambered a x39 RPK barrel for .308. The lack of response leads me to believe that either it is a briliant, cutting edge idea, or those that have, are currently no longer able to type.
Either way, after the Wife and the Dogs, I miss my shop horribly.:bye2: