01-04-2020, 04:53 PM
(This post was last modified: 01-04-2020, 05:06 PM by Kswhitetails.)
OP- Gas should be fully open any time you're changing loads. This sets your baseline and ensures the system functions as designed without being hampered by less than full gas. The only reason to choke your gas is when you're over-gassing the system to the point where it fails to function in some way.
Disclaimer: I do not run adjustable gas blocks in my Grendels. I have at best a solid rudimentary understanding of the AR DI system.
There are three things, as far as I can tell, that need to be considered when setting up the gas system on a gas operated rifle/weapon.
1)Burn rate of the propellant. 2)volume of the gas generated by said propellant 3)pressure generated by the detonation cycle, within the system - as built.
This is understanding and assuming the other "standard" variables. System length, port size, buffer weight/spring weight, plug mass (bullet weight) are all within the "normal" window of operation.
A lot of guys insist (folks I mean no disrespect or offense here, bear with me) that an adjustable gas block is necessary when building Grendel. I'm not sure why. BA was picky when he started settling with final versions of the chamber, propellant selection, and projectile usage for Grendel because he wanted it to work well with the gas systems that had already been designed and proven on the 5.56 AR. When we start tinkering with the variables, we start finding points where we are now not able to use the system as designed. We've moved outside the proven envelope of which the system is known to perform reliably.
So, simply put, this isn't a problem looking for a solution until we start changing the standards with which we operate. Choking the gas, changing the buffer weights, the BCG mass, bullet selection, etc... makes the entire equation fail. Now, we must do the work to determine the limits of the new window in which we operate. We must - out of necessity, put in the work. I mean to say, do - the experimentation, data collection, and variable identification and set the new definitions. All of which are now required to determine our new operating "window" for the gas system.
If I had my 'druthers, I'd start back at the beginning. A standard gas block, buffer, BCG, and spring. If I had to bet on it, the Grendel would show more promise than folks allow it to. Have some faith. BA did EXTENSIVE testing to ensure that Grendel would perform well under the standard configurations already proven with millions of rounds down range on other chambers and calibers.
Otherwise, just learn the DI system. It's just a physics lesson on pressure vessels, pistons, vents, and the related dynamics. Understand the physics, then adjust the system as required to ensure enough pressure, volume, and dwell time are met. It'll work then, I guarantee it.
Disclaimer: I do not run adjustable gas blocks in my Grendels. I have at best a solid rudimentary understanding of the AR DI system.
There are three things, as far as I can tell, that need to be considered when setting up the gas system on a gas operated rifle/weapon.
1)Burn rate of the propellant. 2)volume of the gas generated by said propellant 3)pressure generated by the detonation cycle, within the system - as built.
This is understanding and assuming the other "standard" variables. System length, port size, buffer weight/spring weight, plug mass (bullet weight) are all within the "normal" window of operation.
A lot of guys insist (folks I mean no disrespect or offense here, bear with me) that an adjustable gas block is necessary when building Grendel. I'm not sure why. BA was picky when he started settling with final versions of the chamber, propellant selection, and projectile usage for Grendel because he wanted it to work well with the gas systems that had already been designed and proven on the 5.56 AR. When we start tinkering with the variables, we start finding points where we are now not able to use the system as designed. We've moved outside the proven envelope of which the system is known to perform reliably.
So, simply put, this isn't a problem looking for a solution until we start changing the standards with which we operate. Choking the gas, changing the buffer weights, the BCG mass, bullet selection, etc... makes the entire equation fail. Now, we must do the work to determine the limits of the new window in which we operate. We must - out of necessity, put in the work. I mean to say, do - the experimentation, data collection, and variable identification and set the new definitions. All of which are now required to determine our new operating "window" for the gas system.
If I had my 'druthers, I'd start back at the beginning. A standard gas block, buffer, BCG, and spring. If I had to bet on it, the Grendel would show more promise than folks allow it to. Have some faith. BA did EXTENSIVE testing to ensure that Grendel would perform well under the standard configurations already proven with millions of rounds down range on other chambers and calibers.
Otherwise, just learn the DI system. It's just a physics lesson on pressure vessels, pistons, vents, and the related dynamics. Understand the physics, then adjust the system as required to ensure enough pressure, volume, and dwell time are met. It'll work then, I guarantee it.
Nothing kills the incentive of men faster than a healthy sense of entitlement. Nothing kills entitlement faster than a healthy sense of achievement.