[walnuts666]

I just started playing, I have maybe 7 games under my belt. never used frag grenades and they are really not explained very well in the rule book. I was taught on the fly one day to get the basics and the next week I was playing in a tournament so many of the guys helped me a lot with rules. I play orks if that makes any difference.

 

[Viscount Vash]

Models charged in cover strike at initiative 10. Frag grenedes (frag stikkbomz in your case.) just mean that the charger (if armed with them) goes at the same time.

 

[DaemonsR'us]

When your orks charge marines into cover, the marines are given I10 for that turn since you are charging into cover, your ork frag stikkbomz give your orks I10 as well, so they attack at the same time instead of the marines attacking first, but powerfists and the power claws as well i believe still attack at I1
And marines are just used as an example, the rule applies to any race you charge thats hiding in cover

 

[Deceiver]

when you charge into cover,oppenent strikes first on 1rst rd only (init 10) except for models with init 1 wpns. if attacker has frag grenades then both players strike simo then all init 1 wpns go. draw straight line from attackerto defender to see if attacker goes into cover to attack 1rst.
frag grenades must be purchased by entire unit to be considered having grenades.
if ind char is attatched then he must have grenade too for it to count.