View Full Version : 9mm AK my way
06-23-2008, 07:42 PM
Started on this project back in December and it is just now nearing completion. I am a slow worker, what can I say...
Started with an AK flat and 2xtm magwell.
FUBAR'd the angle of the magwell so I had to start over, good thing I have more flats and ordered 2 magwells. I am using a 16" uzi barrel that was turned and sleeved for me by a member of another site. Add a romi parts kit, phantom flash hider and saiga rifle handguard and this is what you get.
I was originally planning on using a 6 pos. adjustable AR stock but wasnt really diggin the look, so I changed my mind and went with a plain ol' A2 stock instead. I made a sort of "pistol" trunnion for the rear and was trying to figure out where I could find a steel AR recoil buffer tube when it hit me, its just a tub with a threaded hole at the end and I dont need the threads on the open end anyway so I went on the hunt for a piece of ~1.1" OD tube. I found it in an old Roadmaster bicycle frame I fished out of a trash pile awhile back.
Eyeballed 'er straight and welded 'er up.
Then after fiddling around with a CETME parts kit I decided a non-recip cocking handle would be the cats ass since this is a recoil-operated build. Step 1: Aquire G3 cocking tube and trunnion from RobertRTG (good people there BTW!)
Step2: Cut up G3 tube to remove area needed.
Step 3: Section G3 tube and weld AK RSB flange to end to achieve same OAL as AK gas tube.
I should note here that I originally was going to permanently weld the small piece of rail to the gas block to retain the option of running AR BUIS's but decided it looked retarded so I removed it and will be installing H&K open sights in addition to the rail on the RSB.
Next, mock up to test fit and function.
Luckily the G3 parts fit EXTREMELY well with the AK parts. The AK gas piston head fits PERFECTLY into the rear of the charging handle piece and once the outside of the piston and inside of the handle piece were beveled they work very well together. I am a little hessitant to drill and pin the gasblock because of the increase in bore diameter, I'm not sure how far I can go before getting into the bore. For this reason, I installed a set screw for now and it seems to be holding. If it retains its position after test firing, I will probably leave it there and maybe JB weld it in place. The angle of the gas block greatly affects the smoothness of the action but with it tweeked just right it works prety well. A little rough, but I expect it to smooth out with use.
06-23-2008, 07:55 PM
On to the trigger assembly. It seems like the chamber on the uzi barrel is cut a little too shallow for the AK bolt face. The gap pictured below is with the round jammed as far in as it will go.
So I ordered a reamer from Brownells and plan on reaming it out just a little tiny bit more by hand, does anyone see a problem with this idea?
Somewhere along the way I decided I wanted a forward sweeping thumb safety on this mofo, so I made one. Here is the basic idea.
I cut up the rate reducer from my parts kit to make the safety lever:lildevil:
Then I moved on to the detent for the safety. I figured an AR detent and sprng would be cheap and easy, and it was.
How it all goes together
Cut out in rear trunnion
Still waiting on the reamer, hoping to get it done and test fire this weekend.
06-23-2008, 08:22 PM
That is one nice build, i really like the HK cocking tube design on it.
I was wondering where you found the steel Picatinni Rail.
I have been looking for awhile and have not found any.
06-23-2008, 08:27 PM
LOL I just noticed your safe-fire designations Kittens-Violence
HAHAHAHA love it
06-23-2008, 08:51 PM
brownells has steel rail it is pricey however. I make my own on a mill but it is time consuming.
06-23-2008, 09:28 PM
I got the rail from a member of another site that was doing a batch.
06-24-2008, 04:56 AM
I LIKE IT! Lots of great ideas - Saiga HG, your thumb safe (got a good laugh out of Kittens / Violence) and HK tube. A2 stock with shortened rcvr has a nice compact look. Good thinking, nice design. Best of luck on the test-fire - keep us posted
Steve in El Paso
06-24-2008, 12:49 PM
Great out of the box thinking and design.......I like it.
07-19-2008, 07:05 PM
I was wondering where you got the soumi mag wells from? How do you fix the excessive back travel with the shorter cartridge?
07-22-2008, 07:00 PM
The magwell was from Lichtenburg Research, but as far as I know they are out of them right now. What do mean by excessive back travel?
I attempted to test fire this weekend and it no worky. It appears that the bolt face does not properly line up with the chamber so the bolt cannot seat on a loaded cartridge. I'm gonna try hacking up the bolt carrier to make the bolt line up properly and go from there. I warped the receiver prety badly when finish welding the magwell in, I was careless and went to fast I suppose. I fixed that issue by moving the front trunnion and barrel assembly around enough so that the bolt carrier would still move freely. I suspect this is where the chamber fell out of alignment. This is my first kustom kaliber konversion so I'm still learning.
07-22-2008, 10:55 PM
I attempted to test fire this weekend and it no worky
well that sucks, hope you get it worked out
I have been eyeballing the charge handel for a place to attach a axularly pump grip for my semi auto/pump combo idea that will cycle hi velocity ammo SA and would have pump for subsonic ammo also eliminating action noise . need a way to keep the pump from going back and forth in sa mode. your charge handel modifed may work.
08-08-2008, 06:14 PM
Great thinking and great concepts on this build. Please send me pic's so I can post them on our site once you get it finished. Love the safety and cocking handle.
I have sold a ton of mag wells but no one is sending back pic's of their completed work. Is anybody building anything with them besides Afroman??
I made another run of mag wells last month and have some in stock. Also have five PPSH41 mag wells left. Copes is now selling flats for the 9mm conversion.
08-09-2008, 02:46 PM
Awesome, I love the g3 setup. Hope you get the bugs worked out. By the way, I still have that 7.62x25 barrel if you still want it.
Afroman, do you have a picture of the cocking handle bits laid out in order? I've no idea how a CETME setup works, and I'm drawing a blank as to how it looks inside the slotted gas tube.
12-07-2009, 11:42 PM
This is what I would like to try with my suomi
01-12-2010, 10:38 PM
Any luck on that thing?
No luck here. Afroman appears to have dropped off the web, at least under that name. I still haven't figured out how he managed to do a non-reciprocating bolt handle. It might be blazingly obvious to someone who knows how a CETME is laid out, but the tiny, low-resolution exploded views I've found have left me as clueless as I was before.
The Indian INSAS also had a non-reciprocating bolt handle on the gas tube, but I haven't found any exploded views of that, either. What little I've found on the INSAS is in a thread in the general forum.
I've been wondering if the non-reciprocating part is really necessary. I didn't like the idea of gick getting into the gas tube, but... the gas tube gets filled with powder residue anyway, and the gas puffs would then to blow stuff out, and there are no tight-fitting bits there to cause problems. And the slot is a whole lot smaller than the giant cut-outs on the left side bolt hacks.
I'm primarily interested in the gas tube bolt handle because want the handle on the left, and I don't like the big cut-outs most left-side conversions use. Some Valmets and Galils had left-hand bolt handles, and they used spring-loaded doors that slid down as the handle came back, then popped back up.
The sliding door arrangement closes off just about everything, great for operating in a sandy environment. If I could buy the bits and fit them to my gun I'd think about it, but for some reason I don't want to mess around with that kind of fiddly bits, making springs, etc.
Here are some images of the Galil - the sliding door is hard to see in this picture; it's held by the two big-headed rivets or washers, with a ramp at the front for the handle to shove it down as it cycles. I can't find the Valmet picture at the moment.
01-12-2010, 11:49 PM
TRX, look at Afroman's first post in this thread, the G3/CETME cocking handle and cocking piece are shown in the 5th picture down. That's all there is, the cocking piece is a short plug that fits inside the cocking tube. The cocking handle fits inside a slot on the plug, a cross pin lets it pivot and a small spring keeps it folded against the cocking tube when released. BTW, in the 5th pic he has the handle in backwards, the next picture shows it properly installed. At the front of the slot in the cocking tube is a stud, the handle snaps over it and is retained in the forward position until it is unfolded. The inside end of the cocking handle bears against a bulkhead in the front of the cocking tube, when it unfolds it pushes against that bulkhead and levers the cocking piece rearward a bit as the handle unfolds. On a G3/Cetme this is necessary as this lever action is needed to pop the roller system open, it requires a bit of force. Once the handle is unfolded, pulling it to the rear simply shoves the carrier rearward as the cocking piece moves back in the tube. At the rear of the cocking tube is a cutout that lets you rotate the handle upward and lock it rearward.
So what's the relationship of the CETME bits with the head of the gas piston? Does the head of the piston go through the CETME thingamabob? Or does only the shank of the rod slide through it?
01-13-2010, 04:10 AM
Both the G3/CETME designs and this 9mm build are blowback operated, there is no gas piston that enters a gas block and no gas port. On the G3/CETME the carrier simply has a hollow tube that enters the cocking tube and abuts against the cocking piece. Think AK carrier with the gas piston removed and a step inside to capture the recoil spring. On the 9mm AK the piston is just there to give the cocking piece something to push against, it is shortened so it rests just behind the cocking piece when fully forward.
BTW, the G3/CETME is called a "roller delayed blowback", the roller mechanism delays bolt opening until pressures have dropped. IIRC, a straight blowback .308 would require a 30+ lb bolt to resist opening long enough, the rollers allow the weight to be a pound or so.
Both the G3/CETME designs and this 9mm build are blowback operated, there is no gas piston that enters a gas block and no gas port.
[slaps forehead] Of course! Now it all makes sense. Somehow I overlooked the blowback part.
Looks like I'll have to figure out something different.
01-13-2010, 05:43 AM
If I were making a standard AK with a non reciprocating handle I would make a sleeve that slides over the tube. Attach a handle similar to the G3 so that when unfolded it reaches inside the tube but folded forward it exits the tube. Right behind the gas piston head add a full diameter ring for the lever to act against. Locking stud on the gas block similar to the G3 to retain handle in forward position.
Looking at pics of the INSAS it loooks like they use the external sliding tube, but with a fixed handle? They also use a one piece gasblock/FSB placed way out towards the end of the rifle, the gas piston is longer than a standard AK. With a gas piston ring to interface with the cocking handle it wouldn't need to have a retractable lever to engage it, the travel of the piston wouldn't be enough for the piston head to hit it in recoil if it's spaced right. Stripping is probably accomplished by manually retracting the stud on the cocking handle that engages the piston.
01-13-2010, 09:31 AM
Personally not a fan of that left-side gizmo. I understand the why, just not my cup of tea.
The S.A. CR-21 uses a non-reciprocating charging handle for its bullpup configuration. It engages a tab welded onto the bolt carrier. This is the best non-reciprocating charging handle idea I've seen.
Look here, you can see in some of the pics the charging handle, the tab, and the way they are both mounted in the rifle:
You have to have a RSB with a hole in it for the pushrod to slide through. Notice the CR21 has a hole on each side (rld2.jpg) so the pushrod can go on either side. You also have to modify the top cover with a slot and probably some kind of cover for the welded-on tab to ride through. The pushrod guide tube would have to be attached to the outside of the gas tube up front. I might do this with another build, but I really want the Valmet look for this one.
I pulled the upper handguard and top cover off my AKM and did some measuring. The length of the gas tube from the gas block to a conventional RSB is 6.5 inches. The stroke of the bolt carrier until it hits the spring retainer is 4 inches, leaving 2.5 inches of the gas piston sticking out the front of the RSB.
If you made a new gas piston with a longer head, you could screw a knob into the extended area behind the head, cut a slot in the gas tube, and screw a cocking handle directly to the gas piston. Unfortunately the handle would have to be removed to get the bolt carrier out.
You could use a non-fluted gas tube and a floating sleeve inside, the ID of the sleeve allowing the head of the gas piston to slide inside. Put a tab on the sleeve and attach the cocking handle to it. If the handle is at the front, cut the slot all the way to the end of the gas tube where it goes into the gas block. The sleeve would engage the bolt carrier at the back.
To disassemble, remove the bolt carrier, then remove the gas tube - the sleeve should be shorter than the tube - and slide the inner sleeve out from the front.
Hmm, that might work. And my Galil gas tube is larger inside than (the fluted section) of a regular gas tube; there might be room for an operating tube sliding in there...
gas piston OD: .545
Galil tube ID: .685
... and WTF? The Galil tube ID and OD vary .010 down its length. So much for keen Israeli quality control. Well, it *is* an AK, after all...
The closest standard inch tube is 11/16, nominally .687. A 16 gauge tube has a nominal wall of .063, so the theoretical ID is .561. Remove a little off the OD of an 11/16 tube until it slides freely in the gas tube, and you're in business!
Okay, I'm coming up with zip searching for some 11/16 x 16ga or 18ga tubing. As usual, it seems to be one of those sizes listed as "standard" that nobody actually carries.
I could turn something larger down on the OD, but the ID can't be smaller than .550-ish. I don't want to try opening up an ID that deep.
I wish I could find a chart that listed tubing by ID instead of OD; this isn't the first problem of that sort I've run into.