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+--- Thread: Gas system question... revised (/showthread.php?tid=189)
Gas system question... revised - Ihmsa7br - 01-23-2021
Ok maybe I asked the wrong question... Has anyone run into issues with a fixed gas block?
I am building my ARC currently and ran into an issue with my handguard not fitting over the adjustable gas block. Call it a rookie mistake in the current environment, not waiting to verify dimensions with customer service, when inventory changes overnight.
RE: Gas system question... revised - grayfox - 01-27-2021
Definitely want the low profile gas block, whether fixed or adjustable. Mine runs a fixed gb (low-profile) and no problems at all with it, 0.750 journal. Ejection seems right and cycling is smooth.
But yeah, verify that the handguard/gb will fit. I deal with HGs I know about, and luckily this time I had it already on hand. Midwest industries. Also the Matrix (joebob) does fine too. Not sure what inventory anyone has, you'll want to check around if you need a different HG than you have.
RE: Gas system question... revised - Ihmsa7br - 01-27-2021
grayfox... do you by chance peruse the 6.5Grendel forum? The handle is familiar.
Anyhow, I ordered the barrel from SixSigma, then found the 6.5 group and the group buy of the barrels there. So I have the AR24 profile barrel with a .936 journal. Not a lot of parts in stock it seems... and I have been burned by waiting to get an answer and losing out on a part going out of stock overnight. Couple that with missing an image containing dimensions (amazing how many mfg do not add that one bit of useful info).
Once I find a spanner to tighten the barrel nut so I can complete the assembly... I am using a Wojtek Arktos, if for no other reason... being instock. SixSigma is carrying them so it made sense...
after assembly and function test, then next up is mounts and glass... at least those I have a good understanding of already.
RE: Gas system question... revised - grayfox - 01-27-2021
yep, on there too.
Might check with 6sigma on where to find a HG, plus the spanner/wrench...
RE: Gas system question... revised - StoneHendge - 01-29-2021
It would be hard to find an adjustable 0.936" block that will fit under anything other than the most generous rails in normal times. The good news is that fixed blocks arent expensive. It should work and I don't know why it wouldn't work, but you are in uncharted territory for the cartridge in terms of barrel length / gas system length as far as I know. I think the longest barrel I've seen this far is 20".
I'm looking forward to hearing how your barrel shoots - I ordered a 16" to replace my 243 LBC when the day comes. Hopefully that day doesn't come anytime too soon, but it's always best to have a plan these days.
RE: Gas system question... revised - Old Bob - 01-29-2021
Ihmsa7br... Don't know if this helps or not but Wilson Combat has a couple of options for low-profile .936" diameter adjustable gas blocks.
https://shopwilsoncombat.com/Wilson-Combat_SLR-Rifleworks-Sentry-9-Set-Screw-Adjustable-Gas-Block/productinfo/TR%2DAGB%2D9/
https://shopwilsoncombat.com/Adjustable-Lo-Profile-Gas-Block-937-Rifle-Length-Straight-Gas-Tube/productinfo/TR%2DAGBL%2DR/
RE: Gas system question... revised - Ihmsa7br - 01-29-2021
OldBob,
The Wilson GB may might have assembled but would not have had much clearance. I was able to find a handguard locally that will work very well (a supressor model), and if I need more stability on a rest, I can add an ARCA rail. Right now I have to get another barrel nut wrench so I can tighten things up and get it out for some function testing. I need to get an optic mount decided on and incoming. I will use one of my scopes from another rifle till the budget stops hemmoraging from the build and ordering supplies... factory loads arent cheap to get brass... but I saw it stated, you will likely spend as much on the components to load as factory... and if you cant get brass you are dead in the water. With factory... you have something to shoot and get brass.
RE: Gas system question... revised - Old Bob - 01-29-2021
Back in September when I ordered my barrel I bought 200 rounds of ARC ammo -- 100 each, 105gr Black & 108gr ELD-M. The price back then wasn't too unreasonable at $26 bucks a box. I've also resized some new 6.5 Grendel & 220 Russian brass for fire forming whenever I finally get my barrel. Fortunately, I haven't had to spend a lot of dough on components. I have powders & primers from when I was reloading ammo for 3gun matches. The only components I've had to buy were 6mm bullets & the new Grendel & 220 Russian brass.
I have looked at buying more ammo & powders but haven't found any anywhere. Oh, I did find some suitable 6mm ARC powders... In Canada! I'm not sure but I think you need an import license to get stuff from out of the USA.