SIGforum
Thoughts on barrel length for 6.5 Grendel AR...18” or 20”?

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/630601935/m/1630097954

August 10, 2019, 08:53 AM
x0225095
Thoughts on barrel length for 6.5 Grendel AR...18” or 20”?
As the title says...

General purpose rifle for Target/Range shooting and Hunting (Whitetail & Hogs)

Can’t decide between 18” or 20”.

Leaning towards 20”...

Any forum experiences out there ?


0:01
August 10, 2019, 09:31 AM
fritz
Muzzle velocity will likely be some 40 to 70 fps from the longer barrel, depending on load, for similar barrels.

The 20" barrel will weight a little more, with the additional weight depending on brand and barrel profile.

For a target shooting, where you generally don't move around much, a longer barrel improves flight ballistics.

For hunting, a lighter barrel is easier to carry.
August 10, 2019, 10:02 AM
ed308
For target, 20" barrel would be my choice and what I have for my 6.5 Grendel. But for hunting, I grab one of my 6.8 SPC with a 16" or shorter barrel. When hunting, I like light weight and a short barrel. Unlike the Grendel, the 6.8 doesn't give up much when you go short on the barrel.
August 11, 2019, 06:45 AM
fritz
quote:
Originally posted by ed308:
Unlike the Grendel, the 6.8 doesn't give up much when you go short on the barrel.

Fluid dynamics is behind the physics of how much a bullet gains/loses velocity as a barrel length increase/decreases. There isn't much difference in powder capacity for the two cartridges, nor is there all that much difference in bore size.

Sure, the 6.8 is a slightly larger bore, therefore its MV is slightly less affected by barrel length. But it's splitting hairs -- it's not comparable to the MV & energy differences between, say, a 223 Remy and 300 blk, for SBR and rifle-length barrels.
August 12, 2019, 01:56 PM
Phelen_Kell
Suppressing? Get 18. If not, then get 20.
August 12, 2019, 08:06 PM
x0225095
Thanks for all the input fellas.

I got the Atheris 20”.


0:01
August 19, 2019, 09:23 PM
guardianangel762
What ranges are you using it?

I have a 22" for open areas and a 12" for my brush gun.


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But then of course I might be a 13 year old girl who reads alot of gun magazines, so feel free to disregard anything I post.