History lesson! In the early 90s China was selling a pile of semiautomatic Kalashnikov (ak) pattern rifles to America. By executive order, President Bush banned the importation of Chinese rifles. The writing was on the wall and before the importation ban, China rushed to produce and ship as mank AKs as they could into America. A lot of these pressed barrel rifles had bad headspacing. I know of a rifle that had excessive headspace exploding and breaking the locking shoulders of the trunnion. The bolts lugs didn't shear, though. The sheetmetal receiver ballooned and the magazine was blown out the bottom of the rifle! After the failure, the broken parts were carefully measured. It was determined that the headspace was approximately 65 thousandths (.065) of an inch too long. That isn't a big amount of space but plenty to cause catastrophic failure. Luckily, the shooter wasn't hurt. That is when I decided to stick a set of headspace gauges in every AK, I ever acquired (actually I do this prior to purchasing). I was the shooter and the rifle was brand new. It was the long barrel, bipod model AK and was unboxed at the range that day. CHECK the Headspace! People can get seriously hurt. Great video!