Ah that problem, it's a failing of palladium's rule system, and one they refuse to address. (By their rules a main with a baseball bat and a physical strength (P.S) of 20 can do
more damage to a target then a a .9mm handgun or even 12 gauge shotgun fired point blank.

)
as I see it two options:
#1 Use a different rule system that's more current realistic. (Those palladium rules haven't been updated since around the early 1990's?)
#2 tweak the firearms to be more lethal in one (or all) of the following ways.
- Damage from a firearm bypasses S.D.C entirely and goes directly to hp, this makes most firearms lethal in 1-3 shots, with a good damage roll.
-The strike roll is added into the damage roll for more damage. (Whatever you roll on your twenty sider when rolling to strike is added to the damage, I.E a roll of 15 to hit = +15 to the damage total)
Rather then a random die value (i,e 2dr, 4d6 etc..) all firearms automatically do the maximum amount of damage possible per strike. (I.e a 4d6 hand gun does 24 points of damage every hit, a 2d6 pistol round 12 points, etc..)
Using all of these together makes firearms incredibly (realistically) lethal, and even a punk in an alley with a Saturday night special can spell grievous injury or death for an
unarmored character.
Of course when using such optional enhancements it's advisable to make sure the players are able to properly equip their super heroes with abilities or equipment to help protect against these now deadly weapons. (Properly outfitted Punisher style gun bunny characters will now be almost on par with Batman and Johnny Torch in terms of damage capability and posing a serious threat to would be villains.