The 6mm ARC was designed for AR style shooting I believe.
I ventured into the 6mm game about 2 yrs ago after taking a .308 to the local PRS match and seeing the amazing benefits of the more mild recoiling cartridges when it came to spotting shots. I could spot 800+ impacts with a 12lb rifle but when I I shot a 6 BR in a similar weight rifle, I could see impacts at 300+ yds which made adjustments even easier.
I went home and started researching 6mm cartridges and found most were almost identical. Bought a 6GT (because I could get good brass) and went to the next match. A guy in my squad had a 6 ARC and we struck up a conversation. He liked it and it was in an AR platform. Problem was, he was getting 2450FPS in his loads compared to everyone else getting about 2850FPS in other 6mm loads. Maybe when hand loaded that is what he decided for the ARC, I don't really know.
But if you look at the PRS game, lots of support for the 6mm lines…6BR, BRA, GT, Creedmoor….are the most popular I see. Maybe forgetting one or two. Lapua makes brass and it usually can be found for the BR. Alpha and Hornady make GT brass (look online as GA Precision to purchase).
If you choose one of those, you will run about 33-38gr of Varget, H4350 or 6.5 Stabil most likely. The thing I can't recommend is the bullets…not a ton of "hunting" bullets available if that becomes a requirement. Lots of us shoot 105-110gr tgt bullets and most of those are Berger Hybrids, Hornady ELD-M and Hornady A-Tip. All perform great.
Side note, I have a 6GT built by GA precision on a Defiance Deviant action and it is amazing! My buddy has a 6GT built by Blue Mtn Rifles on an Impact 737R and it is equally amazing. If you said which action is smoother and nicer, I would not be able to answer.
Lastly, the 6 ARC I believe has factory ammo available from Hornady and now the 6GT does as well.
Good luck, hope that helped.