What new AR to build.

[dennishoddy]

I've had a complete AR kit sitting around for a long time with the exception of a barrel because I can't think of any caliber that wasn't already covered in the safe. Everything from screamers that run over 4000 fps to 30 cals and pistol caliber lever guns like the .44 mag and so on.
Generated a couple threads on here to get ideas. Great responses, but nothing that tickled my fancy.
Happened on a hunting show which like most is a 30 minute infomercial but it did show a new caliber cartridge brought out by Browning/Winchester called the 6.8 Western.
Basically a jacked up .270 short mag. 170 grain bullets running at 2800 fps. Bullets at that weight and that caliber are long making them fly better at longer ranges.

Here is what is appealing to me, it's a short action cartridge big enough to take any game on the North American Continent.
Short action ='s compatibility to the AR platform which ='s to what that unused AR kit in the safe is going to grow into.
Meet my new Elk rifle.

 

[Oklahomabassin]

AR 10?

The 6.8 Western factory loaded COAL measurement averages right around 2.917".

 

[Hodrod]

I've had a complete AR kit sitting around for a long time with the exception of a barrel because I can't think of any caliber that wasn't already covered in the safe. Everything from screamers that run over 4000 fps to 30 cals and pistol caliber lever guns like the .44 mag and so on.
Generated a couple threads on here to get ideas. Great responses, but nothing that tickled my fancy.
Happened on a hunting show which like most is a 30 minute infomercial but it did show a new caliber cartridge brought out by Browning/Winchester called the 6.8 Western.
Basically a jacked up .270 short mag. 170 grain bullets running at 2800 fps. Bullets at that weight and that caliber are long making them fly better at longer ranges.

Here is what is appealing to me, it's a short action cartridge big enough to take any game on the North American Continent.
Short action ='s compatibility to the AR platform which ='s to what that unused AR kit in the safe is going to grow into.
Meet my new Elk rifle.

Sounds like a plan is in motion....

 

[dennishoddy]

AR 10?

The 6.8 Western factory loaded COAL measurement averages right around 2.917".

AR-15 with short action. AR-10 uses long action

 

[Oklahomabassin]

AR-15 with short action. AR-10 uses long action

2.260" is as long as you can seat ANY bullet to feed from an AR 15 magazine.
The 6.8 Western factory loaded COAL measurement averages right around 2.917".

 

[dennishoddy]

2.260" is as long as you can seat ANY bullet to feed from an AR 15 magazine.
The 6.8 Western factory loaded COAL measurement averages right around 2.917".

I may have to re read but all the articles I've read say the cartridge is short action. Perhaps their definition of short action is referring to a bolt gun vs an AR, which I've assumed is the same definition as an AR-15. Maybe not?
The 6.8 Western is loaded to deliver more energy than the 6.5 Creedmoor, 6.5 PRC or the 7mm Rem. Magnum and it’s short enough — OAL of 2.955” — to work in a short-action rifle.
https://gunsmagazine.com/ammo/the-6-8-western-hottest-newest-cartridge/

• Short action for fast cycling, high accuracy & reduced rifle weight
• https://gundigest.com/gear-ammo/ammunition/first-look-winchester-browning-6-8-western-cartridge

Edit:
Looking it up, the max OAL in my .243 WSSM is 2.360, and I have some additional room in the magazine.

 

[Oklahomabassin]

I may have to re read but all the articles I've read say the cartridge is short action. Perhaps their definition of short action is referring to a bolt gun vs an AR, which I've assumed is the same definition as an AR-15. Maybe not?
The 6.8 Western is loaded to deliver more energy than the 6.5 Creedmoor, 6.5 PRC or the 7mm Rem. Magnum and it’s short enough — OAL of 2.955” — to work in a short-action rifle.
https://gunsmagazine.com/ammo/the-6-8-western-hottest-newest-cartridge/

• Short action for fast cycling, high accuracy & reduced rifle weight
• https://gundigest.com/gear-ammo/ammunition/first-look-winchester-browning-6-8-western-cartridge

Correct short action/long action in bolt rifle doesn't automatically equal AR15/AR10. Technically .308 is short action in a bolt rifle but is the AR10 platform.

 

[dennishoddy]

Correct short action/long action in bolt rifle doesn't automatically equal AR15/AR10. Technically .308 is short action in a bolt rifle but is the AR10 platform.

That’s true.
What I’m saying is that 2.260 OAL isn’t a finite answer for an AR-15 platform as exhibited by the short action.243WSSM which is longer.
I have an additional .100 in my AR-15 short action magazine with a round measuring 2.360 loaded.

Edit, the western won't fit, so the search continues unless I want to seat the bullets deeper or use a shorter bullet to fit that platform which is doable but questionable.

 

[O4L]

The 6.5 Creedmore is a short action round(bolt gun) but is an AR-10 round, for example.

 

[tRidiot]

Which is why the Grendel was developed.

I thought about the .22 Nosler, but I just haven't gotten around to it.