Quote Originally Posted by Failure2Stop View Post
Ok, finally rested from my 24 hours in airplanes and airports, and have access to my source data.

I can't get too specific, as there are proprietary matters, however, I can disclose that we use high-speed video and pressure sensors that are accurate to silly small measurements, and have really smart engineer guys that translate that data for knuckle-draggers like me. I was corrected in that speed of sound was the local speed of sound, not the ambient speed of sound. Mea culpa.

The collected physical data shows that the bolt carrier begins rearward movement in about twice the time it takes for the projectile to travel from the chamber to the muzzle.

As the carrier begins its rearward movement, it travels approximately 0.075" before the cam-pin hits the first angle of the cam path, which gives additional delay to unlocking.
Ok here is my understanding of what happens in an AR in less that the blink of an eye. Explain what I am getting wrong

cartridge is fired in the chamber and the bullet starts its travel down the barrel

bullet passes the gas port in the bore and instantaneously 20,000 psi of pressure travels through the gas block, gas tube and into the bolt carrier.

at this point pressures are so high that they actually push the bolt into the chamber as well as pushing the carrier back balancing the pressures and not allowing the bolt to unlock

when the bullet leaves the barrel pressures drop in the chamber and bore and allow the bolt to unlock and and the carrier to travel rearward removing the spent brass.

that is the way I understand it.