AK headspace ?

[SSwee]

I need some help from those of you that know. One of my builds is a MAK90 that so far has gone with minimal difficulties. After pressing the barrel I checked headspace and it will not lock up on my go gage. Not having this problem before I wanted to check with those more experienced before I attempted to correct it. I figured to press the barrel back out slightly to get correct headspace and re-pin the barrel to the new position. Am I correct in my plan of action? Any other things to do or watch out for?
SS

[Global Gunsmithing]

try various manufactures of rounds, with the just the bolt and fireing pin removed, if it closes on the rounds, then your good to go

[turbothis]

i put a round in the barrel and put just the bolt over the round and see how much the bolt wiggles left and right. i have done this many times and no failures but i am tricky like that!

[SSwee]

Global,
I've thought about pulling the firing pin to see if it would lock up on a round but didn't know how wise it would be.

Turbo,
The bolt head by itself locks up and has about .010" between itself and the barrel chamber. If I stick a go gage in, it catches on the locking lugs enough to hold the bolt head firm but does not fully engage the locking lugs. All together the bolt head engages the locking lugs but does not rotate enough for the carrier to fully close. It lacks about 1/2" from closing.

Just a thought does it sound close enough that I could press the barrel back against the pin to get the few thousandths I need?
SS

[Simon]

I had a problem like this with my Romy build back when CETMERifles was still around. In my case the bolt wouldn't close on a go headspace gauge but would easily close on a round of Wolf. Perro and someone else said they'd had the same problem in the past and recommended that I carefully test fire it for a hundred or so rounds, making sure that the bolt fully closed before shooting.

I don't get to go shooting often, but I think that build has had at least 200 rounds through it by now and it hasn't had a problem.

I think this may be one of those times where the SAAMI standard (which your gauges were most likely made to) and the European standard are slightly different.

[turbothis]

will it close on a round?

[SSwee]

With the firing pin out it closes on a round more than on the gage but still not all the way. I pulled the bolt head and installed it on a round to see the locking lugs. The locking lugs are engaging 1/2 to 3/4 of the way before everything gets tight.
SS

[Otis61]

I had a problem like this with my Romy build back when CETMERifles was still around. In my case the bolt wouldn't close on a go headspace gauge but would easily close on a round of Wolf. Perro and someone else said they'd had the same problem in the past and recommended that I carefully test fire it for a hundred or so rounds, making sure that the bolt fully closed before shooting.

I don't get to go shooting often, but I think that build has had at least 200 rounds through it by now and it hasn't had a problem.

I think this may be one of those times where the SAAMI standard (which your gauges were most likely made to) and the European standard are slightly different.

I would guess that after the first few rounds(20-30) your barrel snuged up against the barrel pin like SSwee sugested. SSwee I think you may be on to something with the barrel press against the pin. Couldnt hurt to try. Then see what you have.

[turbothis]

maybe the barrel should be pressed tighter to the pin.......

[SSwee]

Pressed the barrel back out against the pin and tried. Still did not lock up. Cycled the action empty a number of times and it got to where it would lock up and close on a Wolf Military Classic. Checked the rounds over all length to make sure there was no change. I'm tempted to take to the range and fire a few rounds one at a time to see if it will seat in better. The numbers on the bolt assembly do not match the trunnion. Anyone see this as a totally stupid idea?
SS

[Jagman]

With a matching numbers bolt and trunnion the headspace had been set when the rifle was built, and unless the rifle has been shot to death the headspace will usually be ok, with your mis-matched bolt and trunnion you should really reset the headspace as it has never been done with those parts as a set.
Press out the barrel a bit and drill the pin hole a size bigger, you have already pushed the barrel up tight against the pin so firing it might not move anything.
Better safe,,,,,,,,,,,,,,you know the rest.
Good luck with it though, and just to let you know - if it were mine and it closes on wolf :2pistol::2pistol:
Jagman

[Global Gunsmithing]

Pressed the barrel back out against the pin and tried. Still did not lock up. Cycled the action empty a number of times and it got to where it would lock up and close on a Wolf Military Classic. Checked the rounds over all length to make sure there was no change. I'm tempted to take to the range and fire a few rounds one at a time to see if it will seat in better. The numbers on the bolt assembly do not match the trunnion. Anyone see this as a totally stupid idea?
SS

not a stupid idea, try a few and see if she loosens up a little more, take your go gauge with you