I recently picked up a transferrable AK-47 underfolder, and it's in kinda rough shape.  Not that it matters, but I'm not a fan of underfolders.  I was toying with the idea of getting it converted to an RPK.

Any thoughts among the masses on doing it or no?

Life is short, do whatever makes you happy.

I've actually also got a transferable underfolder AK on its way to me. I've actually never shot a full auto AK underfolder before... would also be really interested to hear any other members' feedback on it.

If you have AK money, then you have the budget to have it converted.  

A krink would be cheaper to do (no reciever work), but there are more of those than an rpk, so definately cool point.     Any consideration on an rpd?  May as well go belt fed

Didn’t realize you could convert a AK to a RPD. I would assume there would be some permanent  mods to the receiver to accommodate the belt fed parts.

If you want a fixed stock but don't want to make a permanent modification there are adapters that let you mount a buffer tube on an underfolder receiver.  You'd have to use an AR style stock which may or may not be desirable for you.

I say do what you want , life is short...... under folders are sexy though . Get a Romanian donkey dong and full auto from the hip baby

You can't

I assume the RPD comment was a typo, bc there are about zero similarities between an RPD and an AK/RPK other than the round fired. An RPK conversion would be cool if you're wanting to really burn some ammo through it though and just bc it would be different. I have to ask what kind of underfder is it? Bc a conversion from an under folder to any other stock design or AK variant is going to require a ton of work and if its something special as is, you'd probably be better off just making up a fixed stock adapter and leaving it?

If anyone has a lead on a Bulgy RPK kit lemme know.  They're hard to come by intact and in good condition....

I think I'm gonna do it.  Now, who to use?  Mario?  JBI?  anyone else (that doesn't have an 18 month backlog)?

A regular AK uses a different receiver and trunnion, you can’t convert it to an RPK.

Maybe you could have a heavy barrel, but that would be about it.

I thought a builder who could flange out a receiver for the rpk trunnion, would be able to do mods for the rpd.   Did not realise rpd receiver was that much different.

Just sell it and buy a transferable Valmet HB conversion....... thats about as close as you can get without being an SOT

I love AK’s, but I do not like underfolders at all. That wobbly stock and awkward cheek weld pretty much ruin what is otherwise a truly excellent combat rifle. If your only experience with full auto AK’s is with an underfolder, you probably will think that AK’s are some sort of sad joke. The fixed stocks and side folders are much, much better, and allow the AK to be used effectively.

Converting an underfolder receiver to a fixed-stock style will require major reconstructive surgery, and if not done by a skilled artisan, will look like absolute shyte.

Converting to an RPK-style configuration is doable, simply by machining the RPK barrel to fit the AK trunnion. I am assuming that your transferable underfolder is a Chinese AK. Those use a “press and pin” barrel which has a 19mm journal at the chamber end. An RPK barrel will have either a threaded chamber end (for use in early, threaded milled receivers), or a 23mm journal at the chamber (for use in late, press and pin milled receivers and all stamped receivers). Both of these barrel types can be used in Chinese press and pin receivers by lathe-turning the journal at the chamber to be a press fit into the Chinese rifle’s 19mm trunnion.

If your transferable underfolder is not a Chinese AK, then it is a Hungarian FEG SA-85, and is so rare and valuable that it should not be converted into an RPK. European AKM rifles use a 23mm press and pin barrel, so a press and pin RPK barrel would be plug-and-play. An early threaded-in RPK barrel could also be used by lathe-turning the chamber end to 23mm.

As was previously mentioned, an RPD is completely different than any AK-based firearm. The only common link between the two is the 7.62x39mm cartridge.

If you go ahead and do it consider two river arms , tell them Declan sent you. He just re blued a sten for me and has done an AK for me in the past.

^ this. RPK uses a 1.5mm thick receiver v.s. the 1.0mm you have plus it uses a bulged trunnion that will not work with your receiver and the rear trunnion and stock will be 0.5mm to small (width wise) due to the difference in receiver thickness. Just get a underfolder to M4 stock adapter and call it a day or sell it and pick up something else imo.

The Chinese stamped receiver Type 56 AK has a 1.5mm receiver thickness, just like an RPK. You wouldn’t be allowed to switch the barrel trunnion anyway, since that is where the serial number is placed. The Chinese receiver and barrel trunnion will work just fine with an RPK barrel, once the chamber end of the barrel is lathe-turned to 19mm.

Has anyone here had any success converting a Chinese underfolder to a fixed stock? I imagine I'll have to wait for someone like Troy of In Range to start taking in new work again, but I'm willing to wait if it's something that's been regularly done before.
(OP, I think this is similar enough to your question that I'm asking in your thread. If you'd prefer otherwise, just PM me and I'll edit and make my own thread)

Thanks for the gunsmithing insight.  I didn't realize there was that much reconstruction involved.

The gun is a Clayco AK.  I too, prefer fixed stocked AK's, as I have a F/A fixed stocked AK-74.

I may just keep this gun as is.  

Thanks to all.

A bit delayed in this reply, but if you can find an early, no bulge, Yugoslavian M70AB1 front trunnion, the RPK barrel parts should more or less fit with minor mods.

Totally different.

You can't.

Just got it back from Mario at POHF and he did a bang up job.

Looking forward to running it.

AKS-74 or get an AK-12 kit.

I have always heard that Mario/POHF does excellent work. Now that I’ve seen your pictures, I can say that I completely agree with that statement.

The new “semi” selector detent, “short” selector stop, and “notched” lower guide rail are all great upgrades. Does Mario make his own selector stops and guide rails, or are these “unobtanium” Chinese parts? I suppose you could modify/re-drill an AKM selector stop, and an AKM guide rail might even work too.

It almost looks like the auto sear pin hole was drilled crookedly in the “before” picture, making the sear pin’s head not seat flush with the side of the receiver; did Mario fix that as well?

Mario really made that “standard 1980s AK conversion” into a much nicer rifle. Congratulations on a great looking AK/Type 56!

It was a hacked job for sure, but I know that the original conversion used a milled AK sear and pin.  So, I just told him to make it right, and he did.  I don't know about the sear hole not being straight, but it's all correct now with the correct parts.

Blasted it today, and ran flawless.