Next Rifle? 6.8? Maybe a 300blk?

[Suputin]

So quick question, if there are a lot of commonalities with the .223, can I just build a 300BLK rifle with AR15 parts, and just change the barrel?

Yes. The only part that is different is the barrel. To run subsonics you require a pistol length gas system.

 

[blaxsun]

Hmmmmm. I have had the AR-10's, fantastic Rifle, just want something lighter and with cheaper ammo and mags. Any pros or cons between the 6.8 or 300blk?

I would say ammunition availability is the biggest con for both. If I reloaded I'd be leaning towards 300BLK, but as it is 6.8SPC is probably more realistic for me.