Training Reference Guide for Pirates [v2]

I'm just wondering where I should train. I'm asking this because I'm not the average gunslinger for my level.

Level: 50
Attack: 483 ~ 854 (with atk pot --> 545 ~ 963)
Bullets: Mighty
Base STR: 40

My equips:
61 ATK Mr. Rasfelt
15 ATK SCWG
4 ATK, 4 STR Pink Cape
Deputy Star
Oceania Cap (ZHelm on the way)
10 DEX Bathrobe
Lightning Earrings (clean) (Have 11 dex earrings for level 55)
6 speed shoes

I think you'd be best at MP3 right now. Sniping on the bottom while having another player on the top 2 platforms.