Ok, bear with me for just a minute. I have read through this forum till I was blue in the face, LOTS of good people and good info!

I have two Ohio recievers coming, one in 7.652, and one in 5.45. The 7.62 is going to be built into a rifle, and the 5.45 will be a Form-1 SBR Krinkov. I already have the parts kit for the rifle, it is an East German kit from Inter-Ordinance. I have built several AR's and have owned a Norinco underfolder for years, I am also a CNC machinist by trade, so I am not totally clueless - but I do have some questions....

Question 1 - Do I have to remover the barrel from the trunnion to do a screw build, if not, should I do it anyway to make it easier?

Question 2 - If I do not have to remover the trunnion, do I need to do headspacing or is the factory setting ok, if so - can I use any bolt, or does it need to be headspaced with the bolt that is going to be used?

Question 3 - I know the AW ban is gone, but do I still need a certain number of US parts in it? If so, withe ones should I replace? Where is the best place to get them?

That's all I can think of for now, thank you for induldging my ignorance - happy shooting!

#1 No you don't, but if you have the ability to do so it will make things a whole lot easier.
#2 On the six matching number kits I have built, headspace has been fine on each. Most assume headspace was done correctly when the kit was originally assembled. If the trunion, barrel, and bolt match then you should be ok. Yes, headspace is done with a particular bolt. Switching bolts can give different headspace measurments.
#3 Yes, you will need 5 US parts (6 if you use a muzzle brake/comp). The receiver will count as one. Trigger set = 3. Gas piston, magazine floor plates and followers, butt stock, pistol grip, and hand guards are your other choices. Tapco and  rpbusa.com are two places I ordered most of my parts from.

Here are some instructions that might be of help.

Thanks on the quick reply, the numbers on my trunnion and bolt DO NOT match, so I'm guessing a headspacing is in order?

Where do I get GO/NO-GO guages for 7.62 and 5.45? If I can get dimensions on them I could turn some out on the CNC lathe in 303 stainless!

dont go get headspace gauges theres bound to b some1 in your neck of the woods with some
a bolt build is easyer but the rivet is better if u have access to tools id go with the rivets
the end result is better and your rifles will b worth more

I got my gauges from bentmetal for $60a set.  Clymer wanted 50 a piece.