Jolly isn't the best nature for Swampert. 60 Base Speed is subject for ridicule, and you don't want to increase that while lowering one of its better stats.
You are utilizing its Attack in your movepool, so I would recommend an Adamant nature
Optimal EVs are 252 Atk, 252 HP, 4 Def/SpDef. This boosts its overall bulk and hitting power.