RIFLE ASSEMBLEDTHIS WAS A CF MILLED PINNED RPK KIT.YOU CAN USE A UNPINNED KIT ALSO.THE OBJECT WAS TO BUILD THE RIFLE AS CHEAP AND SIMPLE AS POSSIBLE.BY PUTTING IT INTO A BENT BLANK YOU WILL NOT NEED TO PULL THE BARREL,OR HEADSPACE.YOU WILL NOT NEED A VERY EXSPENSIVE MILLED RECEIVER.YOU WILL NEED A 4 INCH ANGLE GRINDER,DIGITAL CALIPTERS,DREMIL TOOL,DRILL PRESS.THE OBJECT IT TO GRIND DOWN THE MILLED RECEIVER PARTS TO FIT INSIDE THE BENT BLANK.YOU WILL HAVE TO GRIND DOWN EACH SIDE ABOUT THE SIZE OF A DIME,OR ABOUT 40 THOUSANDS.THE INSIDE DIAMETER OF THE BLANK IS .125.
KIT FROM CF,TRIGGER GUARD DEMILLED

TRIGGER GUARD REMOVED FROM REAR RECEIVER


GRINDING DOWN REAR TRUNGEN



TESTING TO SEE IF SHE SLIDES IN


DONE.RECEIVER WAS A SCREW UP SO DISREGUARD THE HOLES.WILL BE WELDED UP

STARTING THE FRONT TRUNGEN.CUT OFF AT END OF LEDGE.USE USA BLADES



NEXT STEP IS TO MARK THE STUB TO GRIND A SHOULDER INTO THE RECEIVER STUB TO FIT IN THE BLANK.MEASURE DOWN ABOUT .500 THS AND SCRIBE A LINE ON BOTH SIDES.THIS IS THE SAME SHOULDER THAT IS IN A REGULAR TRUNGEN.





TAKE A DRILL AND MAKE ABOUT SIX SPOTS 40 THOUNDS DEEP.THIS WILLLET YOU KNOW WHEN YOU ARE GETTING CLOSE TO YOU DEPTH.CLAMP A PIECE OF METAL ON YOUR SCRIBE LINE AND USE IT AS A FENCE.

START GRINDING WITH YOUR 4 INCH ANGEL GRINDER


FINISHED.KEEP CHECKING THE WIDTH AS GRINDING.SPRAY WITH WATER TO KEEP COOL.


NEXT TO HAVE TO FILE RAMPS WHERE THE BOLT GOES INTO THE TRUNGEN.THIS WILL LET THE BOLT RIDE IN AND LOK UP.FILE AND CHECK AS YOU GO.I SLID IN THE FRONT ASSEMBLY INTO THE RECEIVER WITH THR RAILS CLAMPED IN TO SEE HOW MUCH RAMP I NEDDED.




FRONT TRUNGEN FINISHED

TEST FIT EVERYTHING AND MAKE SURE EVERYTHING LINES UP AND WORKS BEFORE WELDING.I USE FAKE BULLETS TO CHECK CYCLING.USE CLAMPS TO HOLD TOGETHER.

RECEIVER WELDED UP CENTER SUPPORT AND TRIGGER GUARD RIVITED IN


RIFLE ASSEMBLED AND TEST FIRED.NEEDED A GOOD CLEANING,BUT RAN GOOD



FINISHED PRODUCT.RECEIVER WAS DONE ALUMAHYDE 2 MATTE BLACK,REST OF THE RIFLE GONE OVER WITH SUPER BLUE.WANTED THE BATTLEFIELD PICKUP LOOK.SHE CAME OUT GREAT.US PARTS FCG,BENT BLANK,US GAS PISTON,US SLANT BREAK.TOTAL COST ABOUT $225.CF WANTS $800 FOR THEIR RIFLE.SHE CAME OUT GREAT.THE RPK IS A AWESOME WEAPON!

Outstanding!  Great pics on how to do it too.  Did you weld the front edge of the trunion to the blank or just where the rivets should have gone ?

the rivit holes were egged out,so i just welded them.i was going to drive screw the front and rivit the back to make it look more original,but i could not drill the front trungen holes even with a cobolt drill bit,so i just left it welded.i was assured by the welder who does it for a living that it will not come loose.i also installed a recoil buffer.the recoil was reduced alot,felt like a .223.fun to shoot.

Very nice.

Outstanding Big, looks really nice. I still have my RPK to do, this will make it a LOT easier. I had planned on using "U" drives for the frint and back, looks like I may have to pull out my MIG welder. Thanks Again.

I'm working on the same thing, but I did not mill a ledge into the front stub.  That's a good idea.

I bought a belt sander for $26 at HF.  I was able to mill the stubs very evenly.  I did not trust myself with an angle grinder.  I measured the stub and took 1mm off each side and the bottom.  Fits perfectly.

you do not have to mill in the ledge,but i thought it looks nicer this way.i was hesitente on just the welding,but i was assured that if done right it will be no problem.i figure that this weapon was built as a hobby and will be fired in semi-auto,and not very much so the welding will be ok.

Really cool.

if you want to make your rifle look more original,you can rivit the rear trungen and drive screw the front.the rear trungen is held in on the bottom with the triggerguard rivits,so if you rivit the sides of the rear also it will never come loose.it would be easy to drill through the rear trungen because it was milled down.i tried to drill the front trungen to drive screw on top of the weld.i figured if i screwed up 1 hole in the front i would just weld over and leave it which i did.i have a $49 drill press.if someone has a better drill press and a bit that would drill through and into that very hard front trungen without wobble,would have a better chance at drive screw front.

the rivit hole were welded only.i do not see why a tack weld around the front of the receiver would hurt.the stronger the better.i figered that the egged out holes and the big holes for the underfolder gave a lot of surfave for the weld to hold.probally would be a good idea to make bigger holes like my messed up receiver for more weld contact.

Great post and tutorial. This should be tacked.

if someone is not a welder,they could just rivit the rear trunnion and drive screw and rivit the magwell rivit on the front trunnion.i believe the 4 drive screws and 2 rivits on the front trunnion would work fine.

I saw this post back in November. Still outstanding! Did you do the welding/filling in of the receiver yourself?

a freind who welds for a living did it.