so, im looking for a plugin that makes barrel storage bigger like a double chest, there is a plugin that does the same, but with enderchest (also i already played on a server that had this plugin)
You could use Chest++ (Chest Plus Plus), it has autocrafting and basically autosmelting in it, so if you use the plugin smart, you could do some really cool things with it. Also, you could get your double barrel aswell, if you link two chests/barrels, they become one. https://dev.bukkit.org/projects/chests-plus-plus