Understanding AM40 AR

Hello,

I'm trying to figure out best use cases and equipment for AM40

Since I have all AR with 1200 kills and only one Im missing is AM40, I was going to grind kills fast but I cant understand why this weap even exists in this game.

Its slower than M5A1, it has worse accuracy than AK, it has no features like other ARs.

Trying to use it with extended damage mag and muzzle break, yet cant achive proper accuracy.

However I noticed that it shoots really randomly, sometimes you cant hit a single shot into target and sometimes it does 3 headshots in a row hipfiring.

Any suggestions? What tuning do you use with it?

Thx