Trigger or just Jointly Linked

[Matt the Bruins]

Hi Steve, I'm trying to come up with the mechanics for a bunker buster missile weapon, using Tunneling to represent its ability to penetrate fortifications and RKA Explosion for the actual warhead going off. Is having the two powers Jointly-Linked sufficient to account for the explosion not occurring until after the missile has finished tunneling its full distance into a structure/obstruction (and therefore affecting the interior without having to break through the exterior's BODY first), or would I need to add a Trigger as well?

 

For reference I currently have it written up as follows:

Tunneling 6m through 10 PD material, OAF (-1), Instant (-1/2), Linked (-1/4), 2 Charges (-1 1/2) plus RKA 4d6, Area Of Effect (26m Radius Explosion; +1/2), Armor Piercing (+1/4); OAF (-1), Linked (-1/4), 2 Charges (-1 1/2)

 

If it needs a Trigger, I assume the (+1/4) level would be appropriate, possibly with Misfire to indicate a chance of the ordinance going off immediately upon contact (or if the missile is otherwise damaged by accident)?

[Steve Long]

Personally, I wouldn't Link them at all, since it seems to me that it would be possible to set off the bomb, or start a timer on the bomb (perhaps as the villain's dying action!) even if it hasn't Tunneled. I'd just use Trigger. I'll leave it to the GM to decide the appropriate level of Trigger, but what you suggest seems reasonable at first glance.