Javelin has more ammunition, so when it has 30% chance Increase of damage, then you would be getting 30% chance on every rocket. 

Personaly, I use Javelin Rack 16 Dual'd, On a Max Paragon. It almost 1 or 2 shots any mech. I also use Rosa Pilot. 

If you want to use Helix, shoot for 16 or 12 Dual'd, nothing lower. Helix has a farther range and shorter cooldown. However, it can have less damage because If has less amunition. 

I'm not so sure that that's true. 30% probability is 30% irrespective of number of rounds. It's like dice. Whether you roll one time or a hundred, the chance of getting one particular number is always 1 in 6.

The only benefit of having more rounds is that the chance of at least one round getting higher damage is higher. But overall, sometimes less than 30% rounds will get more damage and sometimes more. It should all even out.

That said, javs give the higher probability at lower ranks, so there is definitely that benefit.

@oswalt , just be aware that the higher rank paragon may attract more powerful enemies than before. If you really want to do it, try to make sure that the the rest of your hangar has some good mech+weapon combos.

what I mean is, the amunition (or the rockets) all have a 30% chance of double damage each. but helix does not have like 8 rockets, only like 4 i beleive, so you have a better chance with javilin