Bullet for 6 arc

I run a 90gr Sierra Tipped Game King in my 6ARC gas gun. Leverevolution out of a 22" barrel gets me right at 2900fps. I haven't put this on any game yet, but it is very accurate out to 500yds. As stated above I've killed a lot of deer and hogs with the 6.5 Grendel at lower velocities. A 90gr Speer out of my .277 Wolverine is also good hog medicine. Again, lower velocity than the ARC. It'll work just fine. Shot placement will be important.
 
Do your daughter a favor and get her a better hunting rifle so she doesn't have to experience losing an animal that she hit. 6 ARC would probably get it done inside 100 yds with heavy bullets but beyond that I think it's way underpowered for large game. Especially in a gas gun.
I have two. Both run 105gr Berger VLDH. Out of a 20” barrel I have mine running at 2640fps. That gives it over 1000ftlbs of energy past 400 yards and and over 2000fps to almost 500 yards. That’s plenty for the deer I kill. I’ve also shot plenty of critters with a .223 and it’s pretty effective.

To the OP I’d recommend something frangible like a 105 Berger or go with something like the 70gr hammer hunter and drive it fast. Either will do the job.
 
80gr Speer soft points have been phenomenal from a 15” encore pistol for several years. Velocity should be close, I’ve dropped a dozen or so deer with it out to 250yds. Frontal shots rarely exit and hit hard. Broadside I always aim for the shoulder to catch cartilage and get a nickle to quarter size exit most drop, never had one go more than 60yds. 200ish pound buck through both shoulders I don’t get an exit he went exactly 60yds. This load kills more deer than tongue.
 
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