Should I build 12" or 16" AR?

[SClearman]

I'm a bit put out with my .223/5.56 AR hunting rig lately. I've had some not great performance with 45gr HP and 64gr SP on coyotes. I want something that will anchor them pretty hard. So I'm thinking of building a 6.5. My question is on barrel length.

This will be a hunting gun. I doubt I will shoot it past 300 yards or so at max, and most shots will be 150 yards and in. I plan to suppress it. I like the idea of a 12" barrel with suppressor, I already have a duty gun in 5.56 with an 11.5" so I know how handy it can be. On the other hand my hunting rig now is a 16" barrel .223/5.56 with a suppressor, so I know that is doable as well.

What I want to hear is how will factory 6.5 Grendel do out of a 12" barrel when used on coyotes and hogs and possibly white tail deer within say 200 yards. Will it be better than .223 from a 16" at the same ranges?

What barrel length would you recommend?

Scott

[Bigs28]

I have a suppressed 12" and hunt with the lead free 110g Maker trex bullets. I am perfectly comfortable taking deer and hogs out to 225 yards with it. There are other bullets like the 129g ablr that might extend your range but i have not looked into that. Every deer and hog I've shot has been under 100 yards and has not gone more then 25 yards with vitals shots.

[drewthebrave]

12" is plenty for what you're trying to do IF you can hunt with lead ammo. My state requires lead-free projectiles -- which have a bit less expansion range at Grendel velocities than lead ammo -- so I like a longer barrel at 18" for some more range.

For example, Hornady 123gr SST expands out to ~400 yards (down to 1800FPS) from my 18", but the 100gr Barnes TSX is only good for ~280 yards (2000 FPS expansion threshold).

[Bonas]

12" is plenty for medium game out to 200 yards.

If you don't already have an SBRed lower, keep in mind the ATF has basically banned braced pistols. You might want to consider 14.5" pinned and welded. I don't see much advantage to 16". I'd go 18" or longer, if going longer than 14.5".

[grendelnubi]

To answer your question directly, IMHO, I would not go less than 12" for hunting. Also the 6.5 Grendel with do much better than the 5.56 at any range. I too went the 5.56 route using copper bullets and with hogs it did ok, but my experience with deer was a different story. Since moving to the 6.5 Grendel, I have not lost a single deer.

If you are looking to understand potential velocity data, below is what I have achieved out of a 12.7" with 5r rifling. None of my reloads are max velocity, these velocities are where the accuracy nodes fell.

123 Hornady American Gunner (Factory) - 2277 fps
123 Hornady Black ELD-M (Factory) - 2230 fps
120 NBT (Reload) - 2204 fps
123 SST (Reload) - 2196 fps
129 Nosler ABLR (Reload) - 2174 fps
129 Hornady Spire (Reload) - 2125 fps

Regarding factory hunting loads, people have used both the 123 American Gunner and Black ELD-M for hunting purposes and it seems to perform adequate. Factory 123 SST, ABLR and 129 Spire velocities would be very close to what I have experienced with factory AG and ELD-M.

I have hunted both hog and deer with 12.7" for many years and have taken deer from 25 to 126 yards with it. Ballistically, it has performed very well at those distances. My go too hunting projectiles has been the 123 SST and 129 ABLR, both reloads. You can get the 123 SST from Hornady and in my experience with other length Grendel's, the velocity is always higher than my reloads.

Good luck with your decision.

[LRRPF52]