Lightweight builds?

[JWP58]

So i'm thinking about building a lightweight hunting upper.

Here are my thoughts....

plain jane forged upper
bcm carrier/grendel bolt from AA
AA 18" barrel (maybe fluted)
Apex Hanguard (12")
lightest gas block i can find
Larue spr scope mount
Vortex 1-4x viper scope.

Anyone have a similar build? Kinda wondering how much this upper would weigh in at...

Also what are some FPS numbers people are getting from 120gr bullets out of an 18" barrel?

[Bwild97]

What brand of ammo do you intend on using? Wolf, Alexander Arms, hands loads?

wolf MPT will net you on avg about 2400fps from an 18" barrel, hand loads could get you to 2550fps.

[Whelenon]

For reduced weight go with the fluted barrel, double fluting is even better. Although the Larue Mt. is first class(I've got a LT158) it's relatively heavy at 7oz. If weight is absolutely critical you might want to consider an aluminum cantilever mount.
Also, go with the M16 BC. Yes, it weighs a little more than a standard AR-15 carrier but the functional advantages in a Grendel make it the way to go.

Your on the right track, good luck

[Whelenon]

Here're weights of my complete uppers.

Upper w/16" barrel - 4lbs
Upper w/16" barrel & red dot - 4.75lbs

Upper w/18" barrel - 4.4lbs
Upper w/18" barrel & Vortex 2.5-10x44 HS/Larue mts. - 6lbs

[Drifter]

On an 18" midlength, which often tends to be overgassed, I suggest an adjustable gas block even if it adds an ounce or two of weight. It could probably be adjusted to work with the lighter AR-15 bolt carrier, and perhaps a lighter standard buffer as well if you want to shave every possible ounce. Without the adjustable block, you run the risk of having a relatively violently operating action. Much depends upon the size of the gas port hole in the barrel.

[biodsl]

So i'm thinking about building a lightweight hunting upper.

Here are my thoughts....

plain jane forged upper
bcm carrier/grendel bolt from AA
AA 18" barrel (maybe fluted)
Apex Hanguard (12")
lightest gas block i can find
Larue spr scope mount
Vortex 1-4x viper scope.

Anyone have a similar build? Kinda wondering how much this upper would weigh in at...

Also what are some FPS numbers people are getting from 120gr bullets out of an 18" barrel?

I have a similar build here http://www.65grendel.com/forum/showt...ighlight=build
Weights of various components are listed in the post. I'll be building a dedicated lower and plan to use an Ace skeleton stock which I believe with drop half a pound. The PST 1-4 you're looking at is about 6 ounces more than my scope.

[stokesrj]

I'm getting to old to climb into the places I hunted in my youth as easily as I once did, even then I would leave camp at 3:30 am to be in place by first light to begin glassing the south facing slopes for Coues deer, Javalina, Bear, Coyote and Mountain Lion. So to make it just a little easier I put together a light weight hunting Grendel. AA at the time offered an upper that met my criteria. It used a Satern 14.5" heavily fluted barrel with an integral flash hider machined from the barrel blank. To keep weight to a minimum, the hand guard was made of carbon fiber and the bolt control group was heavily milled. I built the lower from a RRA standard lower receiver, a RRA lower parts kit minus trigger, and added a Giessele SSA-E trigger and a Magpul CRT stock and standard carbine buffer and spring.
I've been extremely happy with this rig, it currently wears a Nightforce NXS 2.5-10 scope in Larue LT104 mounts. It shoots around 1/2 MOA with several loads and even better with it's best loads. Although it gives up some velocity to the 14.5" barrel I have no problems getting well controlled center vital hits from the prone position out to 600 yards if I can read the conditions adequately. And it is truly a dream to handle this rig for close in and/or low light conditions with this optic. Complete with a ten round mag but unloaded it weighs 7 lbs 1.8 oz. Without the mag it weighs 6 lbs 13.2 oz. The upper with scope weighs 4 lbs 8.3 oz.
I really like this rig.
Bob

[pangris]

I like it. Are those barrels in stock anywhere?

[Schwag173]

Stokesrj's rifle pictured above is identical to my build (ongoing), except I opted for an AP Custom carbon-fiber handguard and a fully fluted 18" Lothar-Walther barrel. I'm just waiting on the barrel at this point.

[LRRPF52]

Stokesrj,

That's not nice to tease us with the NF 2.5-10x24 optic.

I would also recommend an upper with no forward assist if you want to cut weight wherever possible, and lube the BCG well before shooting and hitting the field.

[BjornF16]

Stokesrj,

That's not nice to tease us with the NF 2.5-10x24 optic.

Hey...I've been looking for one of those NF scopes! Where can I pick one up?