Looking to build lightweight 6.5 Grendel AR

[cbmax]

Hi all,

For my next project I am interested in building a relatively lightweight 6.5 Grendel AR. I want to use the rifle for target shooting and varmint hunting (coyotes).

I just looked at the Alexander Arms website and they have some pretty cool components in their 2010 catalog. I like the monolithic upper. I live in NJ so I need to build a post ban rifle which includes a fixed stock and a muzzle break (no flash hider). I like the Ace skeleton stock.

What length barrel would you choose? Will I be giving up too much performance with a 16 inch barrel not including muzzle break? Which barrel maker would you choose? What length monolithic upper would be best? What length gas system?

My goal is to have a rifle under 10 pounds with optic.

Please provide me with some input. Also any photos of your Grendel with the attributes I outlined would be greatly appreciated.

Thanks!

CB

 

[cbmax]

Anyone?

 

[TonyAngel]

I don't know how much performance you'll be giving up with a 16" barrel in that caliber. I don't know anything about that caliber, but I used to have this rifle...



This rig weighed in at just under ten pounds, less the bipod, but with a full 20 round magazine. Considering that you'll be going with an A2 stock, which is light as it is, I'd dump the idea of a monolithic rail. It's going to make the rifle front heavy. Either that or add some weight to the cavity of the A2 stock. Either way, you should be able to come in at under ten pounds if you choose your components wisely and only add what you need. If you need rails for attachments, it's pretty easy to drill and tap the tube and put small sections of rail where you need them. You'll come out lighter in the end.

 

[Zak Smith]

I met Bill last weekend. He brought a bunch of neat rifles. If you want a long range rig, by all means get the longest barrel you can. If you want to shoot varmints within a couple hundred yards, the 16" will be fine.

 

[68wj]

You have to call for pricing, but they are good people to talk to anyway. http://ar15performance.com/264lbc_grendel_

 

[GunTech]

6.5 Grendel was designed for the 16 inch tube. You'll be fine. I only shoot Grendel in a bolt gun so can't speak to which AR configuration works best.

 

[68wj]

Barrel length

Try this for barrel length data. http://alexanderarms.com/grendel_ballistics.pdf

 

[Tirod]

From the Wikipedia entry: "The design parameters required the cartridge, in a magazine restricted loading, to be capable of propelling a projectile with a ballistic coefficient of .460-.500 at velocity of 2650 fps in a 20 inch barrel configuration."

The 6.5G was designed for the 20" in the Rifle class, for long distance competition. The case design and slower burning powders are optimized in longer barrels. If most of the coyotes are under 400m, the 16" would do, but that doesn't use the inherent efficiency of the high ballistic coefficient bullets.

Check Les Baer for their version in .264LBC. Either is definitely an improvement over 5.56 whether short or long barreled. If you shoot a lot, reloading seems the preferred approach to maximize accuracy and minimize ammunition expense - which is no worse than most other non-military calibers.

It's somewhat ironic, it had been said the 6.5G was equivalent to .308 at 800 yards, but now the military is refurbishing all the sniper rifles to .300 Win Mag. Oh well.

 

[cbmax]

Thank you all for the replies.

Sounds like I should suck up the extra weight and go for the 20 inch barrel. Now I have to choose which one / type. Should I go button rifling or cut rifling? Manufacturers seem to be Les Baer, Satern Machine, Sabre Defence, Alexander Arms and Lother Walther.

Tony,

Can you tell me more about why you would dump monolithic rail. Why would this be any more nose heavy than a traditional rail system?

Take a look at the Mega Arms modular monolithic rail.

One of the stocks I have been considering is the Ace Socom which I would have to pin and expoxy to be NJ legal.

CB

 

[Rasp65]

I built my Grendel with an 18" AA barrel/bolt and it weighs out at about 8.5 lbs. with a 1x4 Leupold. AA sells a 16" Spartan barrel by Satern that has the muzzle device machined on the barrel and is the lightest barrel. That with a carbon fiber free float tube you could probably get to 7 lbs.

 

[Tirod]

If it's a target rifle, and weight is a consideration, then just use the A1/2 and be done with it. It has a superior cheek weld to most other component built stocks, and those that adjust length of pull or cheek weld are much heavier.

Monolithic rail uppers are definitely not lightweight. In fact, it takes using a carbine handguard length to even get down to the weight of issue handguard halves. The Service Rifle competitors use a free float tube under them, but it weight 1 pound on it's own. Range/bench competitor's add weight to reduce recoil and movement.

Honestly, light weight and long range are often considered a bit cross purposes, but attention to details can make it work. There is a weight calculator on Vuurwapen's blog that can help make comparisons.