Or maybe you could change the actual effect to an effect that occurs earlier or somewhat before the actual eplosion of the frag. For example, change the frag/impact metal effect (not explosion) to the nuke effect and increase the frag grenade explosion delay to maybe 3 seconds, that way as soon as the frag "explodes" the nuke effect (the REAL NUKE effect) will take place, making the frag/nuke effect look more realistic.