Superlative Arms Bleed Off Adjustable Gas Block

Burk Cornelius · Oct 21, 2016

Wall said:
BTW, this isn't how an AR works. It's not a blowback system. The gas travels back to the carrier through the gas tube (bypassing the chamber) forcing it backward causing the bolt to rotate because of the cam. The rotation unlocks the bolt allowing the carrier to continue back to the end of its cycle.

You just got got gunsmith-ed

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jtischauser · Oct 21, 2016

Wall said:
BTW, this isn't how an AR works. It's not a blowback system. The gas travels back to the carrier through the gas tube (bypassing the chamber) forcing it backward causing the bolt to rotate because of the cam. The rotation unlocks the bolt allowing the carrier to continue back to the end of its cycle.

Don't you still have gas pressure in the barrel that is higher than atmospheric once the bolt unlocks which pushes unburned crap back into the receiver?

Wall · Oct 21, 2016

Jesse Tischauser said:
Don't you still have gas pressure in the barrel that is higher than atmospheric once the bolt unlocks which pushes unburned crap back into the receiver?

If so, very little. The gas you get back in the receiver is from the gas tube. That bullet & gas is traveling much faster than your bolt. The muzzle end will be clear well before the chamber is.

If you use steel case ammo, there's a potential that it won't swell & seal the chamber allowing gas to blow by it. It just depends on how hard it is vs how much pressure is being created.