Over Gassed

[cmshoot]

Who's gonna bring up dwell time.........

 

[Dirty J]

If the gas port is properly sized for the caliber/barrel length/gas system length, has the proper buffer/buffer spring for those same criteria, the AR is made of solid parts, it is properly assembled, and you're not trying to run both subs and supers out of it, there is no reason for an adjustable gas block/BCG/etc.

A properly built AR should run suppressed and un-suppressed with no changes or mods to the system when switching in between.

This right here is the trick for sure.

Getting a weapon to eject and feed properly with/without a can is whatcha want. And unfortunately is something many will never attain - especially when shooting a menagerie of different ammo type/brands.

 

[cmshoot]

This right here is the trick for sure.

Getting a weapon to eject and feed properly with/without a can is whatcha want. And unfortunately is something many will never attain - especially when shooting a menagerie of different ammo type/brands.

Yessir. Operational envelope is a thing!

 

[wildbill1973z28]

I hear this a lot on this forum. I am still have yet to understand the concept. Let me explain.
First when firing a firearm, the gas from the powder pushes the projectiles down the barrel until it exits. While the projectile is moving through the barrel the gas continues to build until the projectile exits or all the powder is burned.
The amount of gas is determined by the powder and the volume of space that is has to burn. So the longer the barrel, the more gas. Now from what I have seen a read, most barrels have a standard size gas port and depending on the length they have standard gas systems, carbine, mid and rifle.
So why would say a BCA or PSA barrel be over gassed and a higher price barrel not?
The logics just don't make sense if all other components are the same.

gas X gas X

 

[Blue bio balls]

Just use an AK. My shells fly 40'..

 

[Gadriller]

All my guns have adjustable Gasblocks as I run suppressed 100% time, if it’s not properly gassed it will beat my guns to death running full power ammo as I learned this a long time ago with 308 AR 10. I believe in opening the gas port and installing adjustable Gasblocks to run either supersonic or subsonic reliable on my AR platforms. Control the problem where it starts at the gas port just how I do things.

 

[cmshoot]

You can’t properly make that blanket statement without having all the pieces in the puzzle.

For instance, not all cans generate the same amount of back pressure. They can vary wildly.

If I were gonna run a gun 100% suppressed, I’d do what the FBI HRT (and many, many others) do, and use a barrel with an under-sized gas port.

I do not see a 5.56 reliably cycling with subsonics with a carbine-length or longer gas system, without a bunch of additional mods……mods that would preclude you from then running supers. This is why .300Blk uses a pistol-length gas system.

Black River Tactical sells gas tubes with restricted port sizes in them. You tell them what you’re trying to do, they figure out the math, and send you a tube with the port size that you need. That would be my Plan B.

 

[cmshoot]

You can’t properly make that blanket statement without having all the pieces in the puzzle.

For instance, not all cans generate the same amount of back pressure. They can vary wildly.

If I were gonna run a gun 100% suppressed, I’d do what the FBI HRT (and many, many others) do, and use a barrel with an under-sized gas port.

I do not see a 5.56 reliably cycling with subsonics with a carbine-length or longer gas system, without a bunch of additional mods……mods that would preclude you from then running supers. This is why .300Blk uses a pistol-length gas system.

Black River Tactical sells gas tubes with restricted port sizes in them. You tell them what you’re trying to do, they figure out the math, and send you a tube with the port size that you need. That would be my Plan B.

Okay, the BRT reduced port gas tube would be my Plan C.

Plan A: build a proper gun that doesn’t need adjustables, or need to be choked off like some gimp

Plan B: reduced gas port barrel

Plan C: BRT reduced port gas tube

 

[cmshoot]

None of what I’ve said here applies to .300Blk. That’s the ONLY caliber where I concede that you’ll probably need an adjustable gas block, and ONLY if you want to reliably run subs and supers without swapping parts.

If you’re trying to run 110grn bullets at 2200fps, and 220 grainers at 980fps, and you want both rounds to run reliably outta the same gun, you’re gonna have to change something. Those rounds are so far apart pressure-wise that on paper they don’t even look like the same round. Something’s gotta change.

 

[cmshoot]

You can’t properly make that blanket statement without having all the pieces in the puzzle.

For instance, not all cans generate the same amount of back pressure. They can vary wildly.

If I were gonna run a gun 100% suppressed, I’d do what the FBI HRT (and many, many others) do, and use a barrel with an under-sized gas port.

I do not see a 5.56 reliably cycling with subsonics with a carbine-length or longer gas system, without a bunch of additional mods……mods that would preclude you from then running supers. This is why .300Blk uses a pistol-length gas system.

Black River Tactical sells gas tubes with restricted port sizes in them. You tell them what you’re trying to do, they figure out the math, and send you a tube with the port size that you need. That would be my Plan B.

I was looking for this! Here’s a chart with a well-represented list of 5.56 suppressors. We can a low back pressure increase of 4%, up to a high of 40%. Significant difference.