6x45 AR build

[Loader9]

I'm going to be building an AR in the cartridge 6x45 or the 223 case necked to 6mm. Wondering if anybody on this board has any experience with it. I'm more concerned about the mechanics than bullet selection or performance. Things like buffer spring the same as a 5.56, twist rates, where did you find the parts and dies, etc.
This should make a dandy varmint carry gun with 70gr TNTs at 3000'ps along with no reduction of clip capacity and no mods to the receiver.

 

[5RWill]

http://sskindustries.com/6-5-mpc

Closest i've ever seen seen what your describing.

 

[taylorce1]

I don't have experience with the 6X45 but I built a 6X47 (6mm-222 Rem Mag) on a bolt action Savage. From what I learned if I had to do it all over again I'd run at least a 1:10 twist. The reason is why limit yourself to 55-80 grain bullets running a 1:12 like I did. Using an AR you'll be limited to magazine lenght where if I want I can run single shot much easier.

I'm pretty sure RCBS, Hornady, and CH4D all make the dies. Probably plenty of others make it as well. You can buy ammunition as well from NWCP, and I've read Black Hills is supposed to make it as well but can't find any for sale.