I am interested in the Faxon - how are your groups?
I am a huge 6.5 Grendel fan. I think it's one of the best mid-range cartridges available. The magazine issue is one of the most discussed frustrations people have with the caliber, whether it's a lack of capacity (for those who want 30 rounders) or reliability (Stoner vs. AA vs. C Products, etc.).
I'm currently researching using these magazines (once they figure out the spring issue) with a PSA KS-47 lower and 12.5" upper chambered in 65G as the "best of all worlds" carbine for me.
I was hoping to light the INGO world on fire with this revelation, but it's still in the works, and this post seemed like a good place to bring it up. I've emailed Csspecs about this idea, waiting to hear back.
For barrels, I've been very happy with Faxon. For BCGs, I've had zero issues with Tool Craft.
The 6.5 Grendel forum is another resource for knowledge.
Lastly, these guys are working on a 6.5 Grendel AK. Evocatus Strategic.