another question

Chaplains on or off bikes, give re roll to hit in the turn they charge. if melta bomb targets do not have WS then effectively they are charging every time, if the vehicle does have WS (eg dread) then the re roll only applies on the turn they charge, if they are the one charging.

The re roll applies, in this case, to the roll to hit which is governed by the speed the vehicle moved

This seems a bit of a grey area, since your only allowed to make one attack with grenades, i guess being fearless about it would perhaps help you in placing the grenades, but thats a bit of a stretch. Anyway, there isnt anything that i can see which says you Cant, but there really isnt much that supports that you can.

I think that you'll be hard pressed to find written back up for a ruling, but considering you have to CHARGE to place the MB's I'd say It's a definite yes :yes:

It can't be any clearer if it tried. The rule in the Sm codex clearly says "...may re-roll failed rolls to hit." So it doesn't matter what you are hitting with, if you charge and miss you re-roll.

Thats right, a faile4d melta bomb attack is still a failed attack and the chaplains re-roll works perfectly fine with it.