Best ammo for AR?

[Cortex]

8.6mm technically does the highest damage per shot but takes more AP. Is it the best, or is it best to use lower caliber for less AP per shot?

[Qiox]

One common, and good choice is to have one 7.6 AR that you can Burst twice per turn with. And in your other hand, have the heaviest hitting 9 mm AR that you can craft, which is of course very expensive with respect to AP to shoot. But, you only shoot the 9 mm with the free Burst that triggers from Commando. This is the only way to get 3 Bursts per turn, without any kind of AP haste med or spell.

[Commissar]

Run a 7.62mm Hornet for flexibility when fighting and hold a 9mm Chimera for use when your Commando perk activates. As far as I could tell this was the optimal AR setup and it's worked really well for my current playthrough

[Eternal Bruhmeister]

Originally posted by Cortex Σ:

8.6mm technically does the highest damage per shot but takes more AP. Is it the best, or is it best to use lower caliber for less AP per shot?

I'm currently using the Steyr-Auch which has insane precision, with the burst fire + extra 2 round perk + hit stacks for burst + commando and I can pretty much 1 burst down any (even armored) units reliabily, it also has a high precision bonus so I'd try to pick it up