6.5 grendal

[para1505]

I am thinking I want to build a 6.5 Grendal for long range. It will be a AR15 platform. I already have a 5.56, thought I would go this route so I can use the lower receiver I already have. So could someone tell me what the perferd barrel lenght and rate of twist for long range shooting is for this caliber?

 

[B-boy]

Re: 6.5 grendal

24" barrel not sure what twist ?

 

[country888]

Re: 6.5 grendal

I think most are 1-8.75. This is what mine is. You may see some with 1-8 and 1-9

 

[louboyd]

Re: 6.5 grendal

What do you consider "long range"?
7.5" to 9" are fairly common 6.5 Grendel twists. I'd say 8" is most common. A 24" barrel is also standard for long range and the longest I've seen except on custom builds. Recoil is mild.
With heavy bullets the trajectory isn't very flat but they can still reach 1000 yards supersonic.

 

[FCS]

Re: 6.5 grendal

If you are going to use the heavier match bullets I'd get an 8.75 twist barrel from Satern and +2" gas system if you are going longer then 20".

What is your goal for velocity and with what bullet?

 

[mjh30]

Re: 6.5 grendal

Para, running a 1/8 twist on a 18inch upper in 264lbc, if I was to do it again, I would look at running it at 21/22 inch, to give me a little extra velocity and to take full advantage of the caliber, without the rifle being overly long. Accuracy is outstanding with 30.5 AA2520/123 scenar, velocity 2480, but I really think 4 more inches of barrel would give the rifle a lot more versatility. I think most of the AA barrels are 1/9 with his shorter chrome lined barrels (7.5, 10.5, 16) being 1/7.5. I think 1/8.5 twist between 22/24 inches is one of the best combos for this caliber.

 

[skinnj1]

Re: 6.5 grendal

When I made mine I used the blank I had in the shop a 1:8, went 24" rifle length gas system, .875" diameter in front of gas block. I hear lots of people get by with a 1:9 but why risk it, my understanding is the 123 SMK is the same length cup before drawing just a few grains less core than the 142SMK , they are long...

I have made two friends barrels and went a lighter profile on each of theirs (1 26", .936" diameter radically fluted, 1 18.5" .750 " in front of gas block) both would be much more practical as a hunting setup but mine still weighs less with bipod and optics than my 260 AR with neither!

 

[para1505]

Re: 6.5 grendal

McCourt, I do not know what velocity to go for w/this caliber. I am still researching it. What is a good velocity w/ what SMK buulet do most shoot w/this caliber. maximum distance will be 800 mostly sometimes i wil get to go to a 1000 yards.

 

[country888]

Re: 6.5 grendal

Most are shooting 123 gn bullets.

 

[Unknown]

Re: 6.5 grendal

For practical rifle matches inside of 600-800 yards, I would use an 18 inch barrel as it is handier and easier to transition between targets in enclosed spaces. For matches or use out in the open, I would opt for 20-22 inch barrel.
I have had a 24 inch barreled Grendel and the only thing I would want one that long for again would be a bench gun, or a set position varmint rig. The long barrels are simply too unwieldy.

Alexander Arms now makes lightweight and fluted barrels in various lengths. If I had enough extra cash, I would love to get a lightweight, fluted 20 inch barrel as it would give plenty of velocity, and be quick for target transitions in open areas.

My 20 inch barreled Grendel develops 2550 FPS with the 123 grain scenar bullet. That doesn't go transonic until around 1350-1400 yards depending on atmospheric and meteorological conditions. If I want to shoot further, I'll use a 260 Remington or something like that.