What have you tried? What does it shoot well? Have you shot it yet? How are magazines working out?
The following gem is a secret so do not tell anyone. If you want to shoot small diameter and light weight bullets at deer sized animals and large bullet construction is far more important than anything else. Just say no to bonded and cup and core bullets and say yes to either monolithic controlled expansion solids from companies like Barnes and say Yes to bullets like Nosler Partitions and Swift A-Frames.
I actual hate the 6mm ARC it is not a 243 Win and it is not a 6.5 Grendel and the marketing behind it is almost as bad as the nonsense that compared the 6.5CM to the 150gr. 300WM and claimed the 6.5CM. the winner! Liars will be liars though and sadly when it comes to cartridge comparisons I have not seen any "professionals" that do a good job you can always tell they are angling for a paycheck or industry favor.
Then you have the nebulious talk of "Secrete Military Unit That Must Not Be Named" being the driving force behind the 6ARC and it's performance. No name, no face then not a real thing pure marketing! It is deceptive and cowardly to market something in that way it is almost stolen valor in principal.
So 85gr. to 107gr. tough bullet like a Partition, A-Frame, TTSX with controlled expansion and run on the hotter side of what your rifle likes. Why? In case you hit the shoulder or you are off on range. You are on the raged edge of being enough to get the job done so cup and core bullets even if bonded are unethical. Compared to the cost of a liscense today the cost of a stellar bullet to get the job done is really nothing. Why do I say this? Well in most states you can get 2 bucks, 1-2 doe with doe permit max. Plus 5 shots to zero. If you are the worlds worst hunter and it took you 2 shots per buck and doe and you used 5 shots to zero that is 13 rounds total and 20 rounds come to a box. If you fail to shoot anything you wasted the money on the tags and you still have a 15 rounds in the box left over for next year. On top of that if you only get 1 per year and take two shots to get it that one box of premium hunting ammo will last you for years! So if you do not reload and want to shoot a rifle that is at the bare minimum for the game you want to hunt spend the money and get some premium ammo with controlled expension bullets!
Good luck on your hunt I hope you get limit and fill the freezer!
SOCOM ordered up the 6MM ARC, Barrett made the first delivery of 200 rifles before the public announcement of the cartridge. The 6MM ARC in the Barrett rifles was to be tested and to replace the Mark 12 used by SOCOM. The best guess is special teams, from what I hear for the SEALS as their SPR and DSM rifles were the Mark 12, and for others unknown as they have their own development budgets.
I have a 16" Aero Precision with a Ballistic Advantage barrel in 6MM ARC, with a 1x10x28 LPVO. I also have a Colt A2 HBAR in 5.56 x 45 with a 20" barrel and a 3x9x50 Redfield LE scope.
I also have a 6MM Remington in a Remington 700 set up for varmints.
To compare the 2 ARs, from my experiance for trajectory only the 16" 6MM out past 200 yards outperforms the best 5.56 handloads that I can make. My Aero has a plotted 5.58 arc in its trajectory at 300 yards, the 5.56 is just a bit larger, last mapped at 6.375", I'm mapping new handloads this month.
If we add wind resistance into the equation there is no comparison, the 6MM ARC is vastly superior, starting at about 200 yards, easily 40% better at 300 yards depending on the wind
Energy on target is a minimum of 50% higher for the 6MM ARC over the 5.56 x 45. My AERO Precision is accurate enough for 300 to 400 yard deer, designed for military use out to 800 yards.
Shooting on target with both rifles zeroed at 300 yards, both are 1 1/2" shooters out to 300 yards. HOWEVER, the 5.56 x 45, requires handloads and is wind sensitive, in my area about 30+% of the time precision shooting really is limited to 200 yards 70% of the time.
The 6MM ARC out shoots the 5.56 x 45 significantly at 300 yards with factory ammunition, in my area it will shoot 1 1/2" at 300 yards 90+% of the time.
Both are good rifles and if I get 5 seconds and a moderate rest all the time I'd rather have the 6MM ARC, as my 300 yard hit percentages are extremely high, hits at 800 yards on 3/4 sized silhouettes are reliable. I would use the 103 ELDX or 108 ELDM for game. I use 6.5 Grendel magazines I have 2-5 round and 2-24 round magazines the work reliably.
For varminting I use my 6MM Remington, there's no comparison.