Guys, +1 Windstorm from Urugamosu 2HKO's Gyarados :/
+1 Windstorm 61% - 71.9%
+1 HP Rock 71.3% - 84%
Is it really worth the instakills on Garchomp, Salamence, Dragonite and others?
Oh and this is timid Urugamosu.
Modest is
+1 Windstorm 66.8% - 78.9%
+1 HP Rock 78.5% - 92.4%
And HP Rock still fails to OHKO without SR.
The problem is, you cannot afford to 2HKO Gyrados in any situation since it will OHKO you back (haven't done calcs).
And doesn't gyra get lefties at the end of the turn switching in (on Butterfly Dance)? (This leads to my next point)
What about with Life Orb? I know that isn't a very good item on Moth, but still.
Without life orb, and with one butterfly dance and SR, timid Moth could still KO Salamence with HP rock. Not even modest or life orbed
Dragonite is the main reason I would run HP ice, as Dragonite is only KOed with Modest and SR, and assuming it is not a defensive spread. But really, it depends on your team.
As mentioned before, HP rock has another risk in the fact that it lowers speed IVs by 1. This, however, usually should not be a major problem.
If you are trying to advertise Gale::
Flying super effective: Bug, Fighting, Grass,
Resisted: Electric, Rock, Steel
You already have fire (super effective against Bug and Grass), so the only thing flying hits SE is fighting.
Steel is covered by fire, but Electric or Rock do not resist Fire/Bug offense.
Bug/Fire is resisted only by (monotypes) Fire types. More prominently, we have the Fire/Steel Heatran, resistant to flying. I see how Gale can be tech, but I don't see it overthrowing HP as a main offensive move.
Throw in the fact that you don't even have stab, and you get few important SE hits on walls/counters, and Gale is simply not a very useful move.
What about taking advantage of the weakness to SR and using Swarm+Substitute to boost your attacks? Maybe something like this:
Urugamosu @ Salac Berry/Petaya Berry
Swarm
Timid
HP to activate Berry after 1 Substitute / the rest in Spe and SpAtk
Substitute
Fire Blast
Bug Buzz
HP Rock / Butterfly Dance
Think of this as a revenge sweeper. With Sun support, come in for free into Stealth Rock on something you can force out (which should be a lot), Substitute on the switch, activating both Swarm and the Salac Berry, and proceed to win the match with ridiculously powerful bug and fire moves from behind a sub with boosted speed. With Swarm, Sun, and STAB, bug and fire moves are both boosted by 2.25x, meaning Bug Buzz has a final power of 202.5 and Fire Blast reaches 270. Most priority users cannot survive one of these attacks (Lucario? Nope. Scizor? Yeah right. Dragonite? A reason to run HP Ice perhaps, but Fire Blast does as much as 50%). And heaven help anyone who lets you get a Butterfly Dance under these conditions.
Adding to your post =)
(Probably are wrong)
Calcs for swarm + petaya Modest Urgamoth (not factoring a Butterfly Dance) Bug Buzz
Does 343-404 damage to a 229 Special Defense Swampert.
167-196 on offensive Dragonites
If you do get another boost (from Butterfly/Fire Dance) you do:
222-261 on Dragonite (I think around 50% chance to KO after SR)
And a clean KO on standard 4th gen Swampert from Bug Buzz.
(Sub, Butterfly Dance, Bug Buzz, Fire Dance/Fire Blast)
EDIT: I should mention that I didn't factor in Dragonite's Dream World ability.