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View Full Version : 18" v 20" Barrels for a 6.5 Grendel build


BiggSean
11-30-2009, 8:18 PM
Before I start yammering on, let me preface this post by saying that I searched prior to starting this thread.

Based on my poking around on the interwebs, I understand that a 22-24" barrel will yield optimum performance when taking the 6.5 Grendel out to 1000 yards. I'm not the most experienced shooter in the world, so I don't know how soon, if at all, I will be attempting at shooting out to 1000 yards. I would however like the capability of being able to shoot to 800 yards, with the potential of someday taking it out to 1000 yards if my skills ever allow me to do so. I already have a 5.56 AR-15, so my mid-range niche is satisfied.

That being said, I am debating between the Alexander Arms 18" stainless steel fluted barrel, which includes a matching bolt in the $320 range, and the Sabre Defence 20" fluted stainless steel barrel which clocks in at $620. There is an obvious price difference between the two, but will the extra 2" result in a substantial difference in long range performance?

Provided that I opt for the less expensive 18" barrel, what sort of range can I expect from this rifle? I really don't want to cut myself short in terms of utilizing the full capability of this cartridge, but at the same time, I don't want to build a rifle that is cumbersome to carry around.

Aside from the barrel, I plan on using the following parts:

- Mega billet upper and lower receiver
- Ergo pistol grip
- Magpul PRS stock
- Daniel Defense Omega rail
- Adams Arms piston kit

I haven't decided on my optics or BUIS yet.

rabagley
11-30-2009, 8:24 PM
The extra 2" will buy you about 50fps at the muzzle. Be aware that all of AA's numbers on staying supersonic past 1000 yards were from a 24" barrel.

I have a 24" AA barrel cut it down to 19" and when cut, the new muzzle was non-concentric by about .05" (the company AA shops out barrels to don't use very accurate drills).

I'd go with the Sabre defense unit because it's likely to be a higher accuracy barrel.

cyphr02
11-30-2009, 8:30 PM
been facing the same question lately but found a 24" Sabre Barrel for less than $600 with the bolt included. I know personally, I'd rather do it right the first time then kick myself down the road.

BiggSean
11-30-2009, 8:32 PM
I like to follow that same philosophy. I should probably play it safe and opt for a longer barrel.

Do you know if that barrel is available in a non bead-blasted finish?

1988
11-30-2009, 9:19 PM
I like to follow that same philosophy. I should probably play it safe and opt for a longer barrel.

Do you know if that barrel is available in a non bead-blasted finish?

We don't have to toss a coin when we choose a barrel.

We need to determine the purpose for the rifle and check the ballistics. The bullet weight and muzzle velocity can play pretty good tricks with the same barrel.

Match barrels tend to be pretty heavy. Every inch saved is a major reduction in weight.

Personally, I don't like to reduce a long barrel. I might have a shorter one, but the barrel contour is still the same, which might be overweight.

ar15barrels
11-30-2009, 10:01 PM
Aside from the barrel, I plan on using the following parts:

- Mega billet upper and lower receiver
- Ergo pistol grip
- Magpul PRS stock
- Daniel Defense Omega rail
- Adams Arms piston kit

I haven't decided on my optics or BUIS yet.

If you are going for long range accuracy, ditch the piston and go with the 24" barrel for the extra velocity.
The PRS stock is already going to make it really heavy so you need the extra weight up front to balance it out.
If it's just a blaster, get the 18" barrel and a carbine stock and have at it with a piston...

aermotor
12-01-2009, 12:07 AM
18 vs. 20 in practical use is really no difference imo, key work is "practical" not necessarily what paper says. 16 vs. 20+ is a different story. Sabre is grossly overpriced imo.

If we're only talking barrels I'd personally save my money and get something from Model 1 Sales... 20" for $235: http://www.model1sales.com/item-detail.cfm?ID=BSC265S&storeid=1&image=bar2065.gif&CFID=57094437&CFTOKEN=29596785 — I think you could get to 1000 with that, the right load and decent glass perhaps.

Or check out their 20" complete upper: http://www.model1sales.com/item-detail.cfm?ID=USE2065&storeid=1&image=ustd2065.gif&CFID=57094437&CFTOKEN=29596785

BiggSean
12-01-2009, 9:26 AM
Do any other companies make a reasonably priced stainless 20" barrel?

Bug Splat
12-01-2009, 9:42 AM
Do any other companies make a reasonably priced stainless 20" barrel?

Yes. Lother Walther. Only down side to Woody is he is a PITA to get in touch with. I have a 6.5-284 barrel from them and it is just awesome but was a little work to get. If you email him don't expect a reply for a couple weeks. Your best bet is to try calling. Also you can't order over the web so you have to send him a check and wait for it to clear before he sends your barrel out. Took about a month to get a barrel he had sitting on a shelf. If you have more time then money Lother Walther is a good place to get a barrel.

http://www.lothar-walther.com/473.php

wash
12-01-2009, 10:21 AM
http://www.ar15performance.com/6mmbr__brx

rc50cal
12-01-2009, 11:49 AM
If you are planning on a bench shooting rig, then longer is better. If you are planning on hunting with it or carrying it around, then you will probably want to make compromises and go with the shorter barrel. If you wish to shoot accurately out to 600-800 yards, then you will probably want to invest in a higher quality barrel than the Model 1 or even the standard AA factory. You will probably want an upgraded trigger also.

rabagley
12-01-2009, 10:39 PM
http://www.ar15performance.com/6mmbr__brx

OOoohhhh.... I wonder if Marty Ter Weeme has looked at making a .458 SOCOM barrel out of one of those... Same rim diameter, and the pressure limits of the existing thin-wall bolt are the SOCOM's limiting feature.

thmpr
12-01-2009, 10:49 PM
Go with the GDMR version.

wash
12-02-2009, 8:05 AM
OOoohhhh.... I wonder if Marty Ter Weeme has looked at making a .458 SOCOM barrel out of one of those... Same rim diameter, and the pressure limits of the existing thin-wall bolt are the SOCOM's limiting feature.
I was thinking more of 6.5 BRX if he wants something to reach out 1,000 yards. A bit more case capacity would help.