Caliber Options for an AR from an 80%

[Cpt]

I am thinking about starting a rifle build. What are the caliber options for building an AR from an 80% lower?

For an AR-15 all I am aware of is:
5.56, .223, (.22 with conversion) and 7.62x39.

For an AR-10 all I've seen is .308

Please let me know what other options are out there?

[OrenG]

I am thinking about starting a rifle build. What are the caliber options for building an AR from an 80% lower?

For an AR-15 all I am aware of is:
5.56, .223, (.22 with conversion) and 7.62x39.

For an AR-10 all I've seen is .308

Please let me know what other options are out there?

AR15 lower?

Possibilities are only limited by the uppers available. That includes 5.45x39, 5.7mm, 9mm, .50 BMG, etc, etc, etc.

[joelogic]

/thread

[Droppin Deuces]

I'd go with a 20" 6.5 Grendel and take that sucker out to 1000+

[Cpt]

So the article on Wikipedia is correct about the large number of calibers. If so at which caliber does the AR-15 lower receiver's magazine well become too small. From my limited knowledge on ARs .308 ammo is too big for an AR-15 hence the need for the AR-10.

[Dead*Reckoned]

6.8, .45 acp, 10mm, there are
416 and .510dtc bolt action uppers also. You can go with a crossbow upper if you desire. Basically if you can think of it, and it fits in the magwell, someone has made an ar of it.

[Cpt]

I am currently trying to compile a list of calibers compatible with an AR-15 lower. I will post it up when I have a good amount of calibers and matching uppers.

Thanks for the advice so far, dually noted.

[Cpt]

I found a good trend with good listings.

http://www.calguns.net/calgunforum/showthread.php?t=337969

[vliberatore]

No one mentioned 6.5, 300blk, 50 Beowolf, 50DTC, and 458 SOCOM

[Intimid8tor]

No one mentioned 6.5, 300blk, 50 Beowolf, 50DTC, and 458 SOCOM

I think you can add .450 Bushmaster to that list. With a magwell adapter you can add 9mm as well.

[Droppin Deuces]

No one mentioned 6.5, 300blk, 50 Beowolf, 50DTC, and 458 SOCOM

Someone mentioned 6.5.

[CSACANNONEER]

You can makr or order some sort of AR15 upper in just about any cartridge from .17HMR to 50BMG.

[OrenG]

So the article on Wikipedia is correct about the large number of calibers. If so at which caliber does the AR-15 lower receiver's magazine well become too small. From my limited knowledge on ARs .308 ammo is too big for an AR-15 hence the need for the AR-10.

Well if you mean you still wish to use the lower's mag well then yes. Uppers like the 5.7 and .50 BMG upper have their own way of feeding ammo. The AR5.7 upper uses p90 mags that rest on top of the fore end, the 50 BMG (which is a bolt action IIRC) is either single round only or has a box magazine off to one side of the rifle.

Example:


7.62x39 is about as big as I've seen them go for the AR15 lowers.