There's no certain way. The M4 bullets are hacked by a hacker and then put in, or something along them lines. I hate this as it ruins the game for other players though.

YODO wrote How do people get hacked m4 bullets ?

Not going to teach you, but you essentially spawn them in with scripts through an executor. Don't waste your time trying to find a free executor as you'll be banned in 10 minutes. Do yourself a favor and keep yourself away from scripts and play right.

its not worth modding, the game is amazing and doesn't deserved to be hacked

People get the modded ammo from 'scripts' as stated above! But the game is good. If you want a banned product key go ahead and mod but you wont last very long!

Yveltal wrote People get the modded ammo from 'scripts' as stated above! But the game is good. If you want a banned product key go ahead and mod but you wont last very long!

Standalone doesn't use keys, but I also forgot to mention that if you have ARMA 3, the bans carry over, so if you screw yourself over on the Standalone, you'll have to buy ARMA 3 again too. Since it doesn't use keys, you must make a new steam account and buy the game, essentially starting fresh. It's not worth it. Take it from someone who has bought the game 4 times. (me)