New guy in Pittsburgh

[Professor9]

OK I have most of everything I need, and I found out a few things -

I hope this photo isn't upside down - can't tell on these iphones...

The scope mount in the photo is a cheapo and likely won't use. Will go with a PEPR or maybe a American Defense. Guy I know has one of each for sale.
The barrel I bought used I was told was a Brownells with a 5/8-24 muzzle thread, but the muzzle brake that I went and bought doesn't fit. Wrong threads. Further review shows this barrel to have 9/16-24 muzzle threads, leading me to believe it's an AR Stoner.

Anyway, I am on my way.

[Professor9]

Maybe the photo can be right side up this time. Sorry.

[Professor9]

Rifle is together.

Still need a muzzle device for the 9/16-24 thread.
Gas block is 1.5 turns out from closed and I suppose I'll start from there at the range to determine the minimal gas to hold open the bolt.
Have not yet acquired a scope mount for the Viper.

IMG_1886.jpg

I'd do a better photo, but it's dark by the time I'm home in the evening....

Prof

[VASCAR2]

Looking good, you might look at J & T distributing for a flash hider or muzzle break. J&T/Double Star sell 6.5 Grendels with 9/16X24 threads. Last time I used them their shipping cost was reasonable and they stock A-2 flash hiders and a few different muzzle brakes. Midway also sell a three prong Vortex style muzzle brake with 9/16 X 24 threads.

[Professor9]

Any opinions on this Muzzle Brake?

http://www.shopalexanderarms.com/Muzzle_Devices-6_5_Grendel_SRI_Titanium_Muzzle_Brake_9_16-24.html

[Drillboss]

It certainly looks cool. I don't have any experience with it, but the Grendel recoil is really pretty mild. I just ordered one of these:

http://www.shopalexanderarms.com/Muzzle_Devices-6_5_Grendel_Vltor_Flash_Hider_9_16-24.html

I came close to just getting a thread protector.

[LRRPF52]

Welcome aboard. Sorry I didn't see this earlier. Looking good so far.

What's your gas port diameter?

ETA: Looks like VASCAR got you covered on dealing with the large gas port.

[Professor9]

Welcome aboard. Sorry I didn't see this earlier. Looking good so far.

What's your gas port diameter?

ETA: Looks like VASCAR got you covered on dealing with the large gas port.

Hi. Not sure on the gas port diameter. I assume you mean the hole in the top of the barrel itself, not anything in the gas block. According to Midway USA, the barrel is .750 at the gas port, but I do not know the size of the hole in the barrel.

I believe I've decided on the Aero Precision Ultralight Extended Scope Mount

http://aeroprecisionusa.com/ultralight-1inch-extended-scope-mount.html

and I believe I'll go with the Alexander Arms Flash Hider and bag the expensive one.

http://www.shopalexanderarms.com/Muzzle_Devices-6_5_Grendel_Vltor_Flash_Hider_9_16-24.html

Prof

[Professor9]

Fired seven rounds through the gun today, minus a muzzle device and optic. Intent was to adjust the Black Rain gas block. Started at 3 clicks from full in, all the way out to 22 clicks from full in. Bolt failed to eject the round on any of the seven fired shots. Bolt partially opened once about half way through.
Seemed the gas block didn't make any difference.
Guy I bought the barrel from suggests I might have a bad magazine?
Thoughts? Suggestions?
I might put a standard gas block on and see if it cycles the bolt.
Prof

[PrecisionFirearms]

Since you are using an adjustable gas block, switch to standard buffer. You should not need a H2 buffer in any Grendel. Any Grendel that requires a more than standard buffer has too large of gas port. An adjustable gas block can fix this. From what I can read from your posts, the rifle is either not getting enough gas or has too heavy of buffer or spring. I would replace with standard spring and buffer and turn down the gas. Fix the problem at it's source instead of at the result. If that doesn't fix it and you're sure the bolt carrier or bolt isn't the fault, then you will need to ream the gas port by a few thousandths.

[Professor9]

Thanks. The buffer I have weighs 3.7 oz.
I'll try for a lighter buffer. Prof

[Professor9]

I've got the standard buffer and standard carbine spring installed. Will let you all know how the bolt works.
The reason for my post tonight is the flash hider - I bought the standard A2 Anderson with the crush washer. It appears I need a shim, or a thicker crush washer. The flash hider threads on and is just past proper alignment as it begins to contact the washer. I need a full revolution and I don't think the washer will crush that far.
Any assistance or suggestions will be appreciated. Thanks
Prof

[Professor9]

My bad. I should have researched. On the hunt for 9/16 peel washers, or 9/16 alignment kit. Prof