I had a Romak that had the case separate at the base because the bolt was not fully rotated when fired, resulting in excessive head space. The hammer was not the stock shape and didn't hit the projection on the back of the bolt carrier that it is suppose to stop the hammer from hitting the firing pin if the bolt carrier is not fully forward. It had a 1.5mm receiver and nothing more happened than it blew the top cover off. It wasn't my gun and I was given Bulgarian yellow tip Maxim high pressure 7.62x54R ammo to shoot, which should never be shot in a AK variant.
P.S. My son is building a M-76 in .308 with a heavy target barrel. The barrel threads on a Winchester and Ruger are 1"-16tpi, which is just the right size to thread RPK trunnion which would give you a much stronger barrel to trunnion connection and you can put the gas block where you want and drill the gas port hole as small as needed to just cycle the action. I found that on a belt feed you need the gas pressure to push on the piston a lot longer before it's relieved to accuate the feed cam. Basically you need to convert a short stroke gas system to a long stroke gas system.
I don't know the actual size, but the gas hole in my Saiga .308 barrel is about that of the wire in a 1 1/2 inch paper clip. Not very big at all. I don't even have a drill bite that small.
Thanks again for all of the good info.
I'm back and beginning this project if you still are still willing to loan out your reamer or ream a chamber-John
Well I am back and getting going. Unfortunately I am still in the "honey-do" phase of coming home and shop time is stolen in short bursts.
I stripped down my old RPK Carbine that I didn't like, rented a reamer, extension handle and go/no-go gauges from "reamer rentals" and did the chamber today.
For the record, that was EASY. If I was to do it again, the big extension T-handle they have is definately worth the extra $5. I just went slow, used lots of oil and took my time. It took me maybe an hour and a half, but now I have a yugo RPK barrel in 308, bolt opened up to the 308 head via dremel and headspaced perfectly. Just a little more to go, right??
What could go wrong???
I'm going to be following your project. I wanted to do one in .308 but the ammo prices nixed it. Looking good. I hope you keep posting pics as you go
Steve in El Paso
Looks real good so far. Keep going the way you are and you will have a great build. Don't hesitate to ask for advice from those who have built a MG47. One in 308 will be very nice.
P.S. Glad to see you got back safely.
Thanks for all the help guys. I hope I can pull it off. It will be a slow one though. Today, I will be finishing drywalling the new bathroom! My wife is not keen on the idea of gun-ports in the shower. I wanted armor plate in the walls, but she wanted conventional insulation. She is such a buzz kill.
I'll be keeping track of your build as well. I have been wanting to do such a build for years. Lord knows how long that parts kit will set in the box. It has been three years so far.
Well, the reciever's slapped together. I got all of the drilling and tapping done, but left it the full length of the 24" bars. I figured I will have to lengthen it about 12mm so now I can cut it later. I used tan paint for the layout, that's why it's yellow looking.
After tapping the first three, I broke the first rule of tapping and chucked the tap up in my cordless drill (don't tell my dad, he'd whup my ass) but with oil all over had no problems.
Instead of the 1/2" angles, I used 3/4" for extra strength....aw who am I kidding, I bought the materials from memory and grabbed the 3/4. It worked fine though. I'll have to mod the FCG slightly from the plans, or I may just cut them down some.
I need to buy the rest of the cap screws, but it is going together well. Thanks again SS.
And the obligatory mock up.