Is my gas tube too short?
- Thread starter Despotes
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is your gas tube too short? yes.
will it work? probably, depends on how generous the gas port is drilled, and whether you're shooting "strong" ammo, or weak ammo.
some AR-10 barrel manufacturers adhere to the Armalite gas port lengths, which are about 3/8" longer than common DPMS LR-308 gas port lengths. The DPMS LR-308 barrels use the common AR-15 length gas tubes. So you'd need to get a genuine Armalite AR-10 rifle-length gas tube, which is about 15-1/2" long, compared to 15-1/8" for the AR-15 rifle-length gas tube.
I think the Armalite AR-10 gas tubes are available from Armalite. I believe Wilson Combat also uses the Armalite gas tube length, not sure though, if so, they also probably stock the Armalite AR-10 gas tubes.
just curious, which barrel mfr is this? There's only a few that adhere to the true Armalite AR-10 gas port location dimension.
One of the benefits of this is that this gas port location provides compatibility for the use of AR-15 drop-in handguards on the AR-10 platform.
for example, barrel using Armalite AR-10 carbine-length gas port location with drop-in handguards:
will it work? probably, depends on how generous the gas port is drilled, and whether you're shooting "strong" ammo, or weak ammo.
some AR-10 barrel manufacturers adhere to the Armalite gas port lengths, which are about 3/8" longer than common DPMS LR-308 gas port lengths. The DPMS LR-308 barrels use the common AR-15 length gas tubes. So you'd need to get a genuine Armalite AR-10 rifle-length gas tube, which is about 15-1/2" long, compared to 15-1/8" for the AR-15 rifle-length gas tube.
I think the Armalite AR-10 gas tubes are available from Armalite. I believe Wilson Combat also uses the Armalite gas tube length, not sure though, if so, they also probably stock the Armalite AR-10 gas tubes.
just curious, which barrel mfr is this? There's only a few that adhere to the true Armalite AR-10 gas port location dimension.
One of the benefits of this is that this gas port location provides compatibility for the use of AR-15 drop-in handguards on the AR-10 platform.
for example, barrel using Armalite AR-10 carbine-length gas port location with drop-in handguards:
yes, Faxon uses the Armalite AR-10 gas port location standard, instead of the AR-15 or DPMS LR-308 gas port location. I have several Faxon AR-10 barrels, in both 308 and 6.5CM, and I use the Armalite AR-10 gas tubes for them. My picture above uses a Faxon Big Gunner barrel.
Fulton Armory also has the Armalite AR-10 15.5" gas tubes in-stock.
happy with the Big Gunner? yes.
as you can see I built it as a 308 plinker, "battle rifle" style. With a fixed 6x optic with BDC reticle, I was getting hits on steel silhouettes out at 800yds, with decent ammo.
separately, I would recommend an adjustable gas block for all AR-10 builds.
Faxon said it shouldn't be any problem and it wasn't today. Just shot a few rounds. First rd empty mag bolt locked back. The remainder ejected hot around 2 o' clock. Winchester Power Point 150gr.
That's with a heavy 5.4oz buffer. Will try the adjustable gas block when I buy more ammo and see how accurate this barrel is. It's very well balanced and feels light.
That's with a heavy 5.4oz buffer. Will try the adjustable gas block when I buy more ammo and see how accurate this barrel is. It's very well balanced and feels light.
What did the gas system state for the barrel when you bought it? 20" should be a rifle length gas system.
Texas Speed Bump
Well-Known Member
I don't have a lot of experience building AR10/LR308s but the LR308 I did build (with help) turned out amazing. It's DPMS lower with a McGowan 16" barrel. Despite the 16" barrel, we used a 'rifle length' gas tube with an adjustable gas block. Initially however, even with the gas block opened all the way up, it still didn't cycle reliably so rather than putting a shorter tube on it, I took it to a machine shop and had the gas vent drilled out a bit more. Once that was done, I dialed in the gas block and it cycled perfectly and reliably. The thing that I really like is that with the longer gas tube, this 308 has the recoil of a 223, which makes it perfect for what I built it for...hogs. BTW, that's it in my picture.
Rifle length is tooooooo long for 16" barrel on a 308win. However you could try light weight bcg, buffer and reduced weight spring and it could function? This only a chance of working, bit couldn't tell you for sure. Mid-length would work better than rifle length in this case.
cohunt
Well-Known Member
"Is my gas tube too short?"
That's something you don't want to ask your girlfriend for sure
That's something you don't want to ask your girlfriend for sure
Get a gas tube stretcher…
They're in the same aisle as the wire stretchers…
They're in the same aisle as the wire stretchers…
