If your ejection pattern is that far then its very over gassed and needed to be remedied. Its really hard on the gun to throw brass that far long term on multiple parts. Well tuned AK's will last well past 75k rounds.
You guys should practice on some HK Burst packs, it'll make most of this stuff look easy. Had a Browning BLR once I had to thread and disassemble. It was also a nightmare.
Its actually turned into a business at this point somehow. I got this M47 Patton in last week to disassemble and fully restore. Also have a East German BMP1 that I bought and need to go through.
Right now just around my warehouse on 3 acres, but I will just put them on the road in the summer and go 1.5 mile down the road to the 36 acres I have and tear all my **** up.