what the post above said.I'm gonna hafta figure out headspace for this x25 build that I'll be starting here soon. The headspace is one issue that concerns me since I am not totally sure on how to get it right on this build.
I've never really deal with headspace issue's in my 2 previous builds.
If I recall correctly your barrel had the protrusion set to give the same bolt clearance as a regular AK bolt. so tere is pleanty of protrusion.on a blow back you set it up were the carrier hits the trunion just shy of the the bolt face hitting the barrrel face. On a gas op, You use the correct guage to set head space.