Riot, instead of nerfing GPs barrel numbers...

How bout you do this instead? Get rid of the ridiculous armor pen on them. It makes the damage ridiculously bursty when coupled with a crit, Tri Force proc, and high AD.

Instead, I suggest you replace the armor pen with an armor shred that lasts for a good while, make it so that his barrels are the set up with some initial damage, the slow, and an armor shred, but require GP to follow up on the explosion and scrap with the person for a bit in order to get their full power.

He could still potentially deal a lot of damage if he goes in on someone and he'll also be able to increase the damage of his team come late game, but there won't be as much of 1 barrel taking off 90% of your health stuff that is so frustrating about the ability.