"slam firing"? i searched the forum but i could find anything. i just want to know what it is. and why is it bad and how can i tell if i am doing it?

Slam fire is caused when the firing pin goes forward upon the bolt closing, casing the chambered round to fire.
This was an event that happened with older ARs that had heavier pins (inertia).
Also can happen to weapons without firing pin safety blocks, when the weapon is dropped.
Next time you clear a chambered round from your AR, look at the primer, it will have a slight dent from the pin tapping it.
This is normal, so don't worry.