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Re: MAK-90 rebuild

Posted: Sat, 11 Jan 2014 21:27:24
by safaridave
The FSB was pretty easy. I used my press tool to support the FSB and used a couple of pennies to protect the barrel crown. The tolerance was TIGHT... it didnt move until I heard a loud BANG and then it jumped a few millimeters... then it went out smooth.
fsbpress.jpg
fsbpress.jpg (66.29 KiB) Viewed 2450 times
Got it out most of the way but I ran into an obstacle.. how to get it completely out?
fsbpress2.jpg
fsbpress2.jpg (53.39 KiB) Viewed 2450 times
Seems a 10mm socket is perfect for pressing the barrel the rest of the way out.
fsbout.jpg
fsbout.jpg (133 KiB) Viewed 2450 times
Next the gas block...

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 14:30:24
by safaridave
My apologies for my long absence. Anyway...next is the Gas Block. Not as easy, though.

I used a small pipe tool to wrap around its collar.
GBoff.jpg
GBoff.jpg (104 KiB) Viewed 2412 times
But the darm support point broke and I had to cut it off..
gbcut.jpg
gbcut.jpg (125.95 KiB) Viewed 2412 times

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 14:41:50
by safaridave
Here is the barrel ready to be repoped. I eyeballed the alignment then used a string from the rear sight to the front sight to see if all the parts lined up... they did.
barrelrepop1.jpg
barrelrepop1.jpg (105.63 KiB) Viewed 2412 times
Now I press on the gas block..
GBon1.jpg
GBon1.jpg (45.08 KiB) Viewed 2412 times
Once the GB is on you MUST make sure the gas port lines up with the gas port on the barrel.

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 14:46:07
by safaridave
So I take an appropriately sized drill bit..
GBon2.jpg
GBon2.jpg (93.09 KiB) Viewed 2412 times
and make sure it goes through...
gbon3.jpg
gbon3.jpg (105.08 KiB) Viewed 2412 times
Its important to do this... the gas port is critical to the rifle cycling rounds. If its too small (by being misaligned), it wont cycle reliably.

If it would have not went through I'd just press it off and realign it. Use a flashlight to make sure the alignment is correct laterally and vertically.

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 14:54:11
by safaridave
Another check to do is put on the upper gas tube to make sure it aligns. The bolt carrier and gas piston should be in as well to make sure they cycle smoothly.
gbcheck1.jpg
gbcheck1.jpg (97.65 KiB) Viewed 2411 times
Now to get the FSB on... a little tougher but not too bad.
fsbon1.jpg
fsbon1.jpg (56.58 KiB) Viewed 2411 times
Now the barrel is looking like it should..
barrelcomplete.jpg
barrelcomplete.jpg (115.03 KiB) Viewed 2411 times
Time to drive the pins back in.

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 14:56:57
by safaridave
Now that the pins are in... (a lot of hammering involved). The "un-neutering" of the barrel is complete, and it will now hold a cleaning rod and bayonet like Mikhail would have wanted it to.
barrelcomplete2.jpg
barrelcomplete2.jpg (82.08 KiB) Viewed 2410 times
Now we should focus on the reciever.

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 15:07:55
by safaridave
Here is my trigger guard jig and reciever. Yeah its been a while since the receiver showed its face... but hopefully it will be made whole again :wave:
tjig1.jpg
tjig1.jpg (103.09 KiB) Viewed 2410 times
I have preplace the rivets in the holes with the guard and selector stop.. (make doubly sure the selector stop is on the correct side)
TG1.jpg
TG1.jpg (110.43 KiB) Viewed 2410 times
Place it on the press and get ready to crush.
tg2.jpg
tg2.jpg (63.48 KiB) Viewed 2410 times
NOTE: since this is a Chinese AK there is only one rivet per side of the TG. Normally you can place all 5 rivets, including the rear in the jig and press. Not so here... I have to use one pair of the jig's rivet dimples and the do the rear rivet in a separate operation.
I find doing the TG first is easiest. You dont have to crush the rivets around the lower rails... and since this flat uses RPK rails... they are HUGE and might get in the way.

Re: MAK-90 rebuild

Posted: Mon, 27 Jan 2014 15:18:28
by safaridave
Here are the crushed rivets.
tgcrushed.jpg
tgcrushed.jpg (77.64 KiB) Viewed 2407 times
Now for the rear...
tgrear1.jpg
tgrear1.jpg (80.99 KiB) Viewed 2407 times
And its done...
tgrear2.jpg
tgrear2.jpg (119.39 KiB) Viewed 2407 times
Now its time to fire up the spot welder. More pics shortly.