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View Full Version : Barrel length and Ballistics.



Wally Bear
08-03-2011, 05:29 PM
I am getting ready to build my first 6.5 Grendel. One of the things I would like to know is how does the length of the barrel effect the velocity?

I would love to have a 16" barrel, but how does this compare to an 18" or 20" for velocity and energy? I want this based on factory ammo for now.

Does anyone have practical experience with this?

This will have a lot of bearing on what I choose for a barrel and even my optics.

bwaites
08-03-2011, 05:39 PM
You can figure 25-50 FPS loss per inch of barrel.

Barrel length really is more dependent on use. If you are going to be hunting, then a 16-18 inch barrel will probably serve your needs best, since hunting shots with the Grendel will most likely be inside 400 yards, and from most hunting expericence, inside 200 yards.

(18" is Bill Alexanders personal favorite for that use.)

Target shooters may want more barrel, my Grendel has a 28" barrel, but its not really a practical hunting rifle, except maybe for prairie dogs.

My other Grendel is a 20", which works fine for everything else I do.

That said, I have a friend who uses an 11-12" for deer hunting, because he can hunt suppressed where he lives!

Wally Bear
08-03-2011, 06:16 PM
Being over here on the wet side of Washington, most of my shots are less than 100 yards. However when I run over to the east side of the mountains for some coyote hunting I am looking to buck the wind out to 300-400 yards. Beyond that is beyond my abilities. It seems to me that the 16" will be just right for my situation.

bwaites
08-03-2011, 06:20 PM
Where do you come for coyote hunting? I'm in Moses Lake, and so is another member or two.

LRRPF52
08-03-2011, 07:42 PM
Being over here on the wet side of Washington, most of my shots are less than 100 yards. However when I run over to the east side of the mountains for some coyote hunting I am looking to buck the wind out to 300-400 yards. Beyond that is beyond my abilities. It seems to me that the 16" will be just right for my situation.

How tall are you? If you are 6 feet or more, I would go with at least an 18" for hunting. Fit the gun to you if you will be carrying it while stalking for your hunts. Go with a lighter medium-weight contour barrel, and lean towards lightweight for your furniture & accessories. If you are 6'2" or higher, I would lean towards a 20" pipe. When Bill is holding his 28" PRS-stocked Grendel, it looks like a toy.

Wally Bear
08-03-2011, 08:44 PM
Where do you come for coyote hunting? I'm in Moses Lake, and so is another member or two.

I usually head down to Goldendale or Bickelton. I also like to hunt around Appleton. If I had an invite, I would love to make a trip over to Moses Lake.

Wally Bear
08-03-2011, 08:46 PM
How tall are you? If you are 6 feet or more, I would go with at least an 18" for hunting. Fit the gun to you if you will be carrying it while stalking for your hunts. Go with a lighter medium-weight contour barrel, and lean towards lightweight for your furniture & accessories. If you are 6'2" or higher, I would lean towards a 20" pipe. When Bill is holding his 28" PRS-stocked Grendel, it looks like a toy.
I have had a lot of abdominal surgeries (seriously a lot) so the lighter the gun the preferable. Also I need to keep the weight as close to me as possible.

Wally Bear
08-03-2011, 08:59 PM
well after reading through the forum. I might purchase this barrel http://www.model1sales.com/index.cfm?fuseaction=category.display&category_id=648 and a bolt from AA and just convert my current AR. Then the extra bolt and barrel will just be for spare parts for my wife's .223.

bwaites
08-03-2011, 09:23 PM
well after reading through the forum. I might purchase this barrel http://www.model1sales.com/index.cfm?fuseaction=category.display&category_id=648 and a bolt from AA and just convert my current AR. Then the extra bolt and barrel will just be for spare parts for my wife's .223.

Although some have been happy with Model 1 sales barrels, some have been disappointed as well. They are not a licensed Grendel manufacturer. If you want a lower cost Grendel, I would suggest J&T Distributing:

http://jtdistributing.net/store/page120.html

bwaites
08-03-2011, 09:26 PM
Or...contact JWH, the owner of the forum, and see if he has any fund raiser AA barrel/bolt combos left. (He sells them from time to time as fundraisers for the board.)

bwaites
08-03-2011, 09:27 PM
I usually head down to Goldendale or Bickelton. I also like to hunt around Appleton. If I had an invite, I would love to make a trip over to Moses Lake.

We'll have to get together this fall/winter, though I'll be the first to admit that I hunt coyotes, but seem to have better luck with targets of opportunity! :)

Hoot
08-03-2011, 11:56 PM
I have an E.R.Shaw 24" barrel and the bore finish was the finest I've ever gotten in any affordably priced AR barrel I've ever bought. The bolt that came with it was an AA bolt. Out of the shipping tube, a dry patch went through like a knife through cold butter. Came out clean as a whistle also. I don't know what they do to them after reaming, but if I bought a barrel that was supposed to have been lapped after reaming, that one would have been how I would have expected it to feel. No significant leading right from the first shot, though I did a short break-in routine as a matter of habit. It wasn't needed. That was my experience with the only E.R. Shaw barrel I ever bought. It shoots one ragged hole at 100 yards with the right loads if I do my job.

Hoot