Funker posted this great slow motion video of a few guns, the first is an AR-15 and it shows some truly interesting things.
First there is gas that is bled on both sides of the FSB in the area of the gas tube roll pin.
Second is the great showing of how the gas is vented from the BCG, this was really interesting seeing just how much gets vented and when. It’s a great video of the system and how it works.
https://www.youtube.com/watch?feature=player_embedded&v=uYfvRSV1Jno
That was pretty cool. All of that happens so fast, I forget all the actions that are taking place.
Interesting seeing two separate expulsions of gas from the carrier vents.
-Jax
The gas tube/block leakage becomes apparent when you run a lo pro with a hand gaurd over it. There’s some blackening that occurs in that area until it cloggs up with carbon.
And on occasion some blackening of the hand. 
-Jax
I think that AR was overgassed.
That first blast of gas is leakage past the gas rings.
The second blast is when the two “dump” ports are exposed.
Im not so sure. If you look at where the carrier is when the first blast happens the bolt will be mostly unlocked and should have room for it to vent.
Always understood how the system worked but seeing it in slow motion with such high picture quality really lets you “see” how the system works. Pretty cool.
I will say that the .50 cal is just wicked. The amount of awesomeness when that round leaves the barrel is insane.
I was not impressed. I didn’t like them playing around with the speed. It looks like the bolt carrier accelerates half way through the stroke and it cannot. Also, I did not like the cutesy way they divided the screen into three bands. Very artsy but not very informative.
Really cool.
I wish I had the room/cash to justify a 50. Very cool video.
Very cool to see the different stages of “ignition” me like! The .50 was just wicked awesome!
As soon as gopro comes out with a camera that runs 3,000 frames per second, I’ll make vids like that too.
Pretty neat. The last expolsion was cool.