If an when, Ill be doing a bolt from scratch . It will need to be shorter from the bolt face to the back of the firing pin . the EOD biolt is designed for a standard spacing from the bolt fact the breach face it looks like .Shortening the receiver is a big pain in the ass. (Get ready to pull your hair out.)
I know, I shortened the receiver on my 9mm AK.
What I have in mind will really likey only share the AK trigger group positon an the grip location .
If im going to build a blow back Im not going to try to make it look like a gas gun there is no reaosn for certain things if you dont need a gs piston an GB why have it?
like you mentiond you will ned a custom bolt to go much shorter easly . You dont need a 2/75 inch long trunion to hold in a barrel . so you can take some right off the front if you use a custom barrel mount block you can still leave the breach face inthe stock locstion an make the recvier about 1" shorter right off the bat . After that you move the mag back as far as possible an the shorten the bot as recured an then ove the trunion barrel back to were it will feed correctly .
IM working on a bolt idea my self If I get time an money ill build them .
how was the EOD bolt other wise was extraction OK ?