Trouble With All BB Party

[epiotti]

I recently started a party with all BB's. I know all about how their unequipped attack is 2x their level and all that other stuff. I actually found it better to start using my BB's unequipped at level 7, even though their weapon provided an attack rating of 21 at that point. Anyway, I am currently level 8 and having a real difficult time with Astos. In general, the BB's do 1-2 damage per attack on him, with semi-frequent criticals of 25-30 damage. However, this is not enough to kill him. Is there something I am doing wrong or am I just not at a high enough level yet to kill him? What level should I get to before trying to defeat him? I haven't played a four party game in a while, but I do recall beating him by level 8 many times. The last game I played was a single fighter, so I really don't remember all this stuff. Thanks for the help.

[Axethorn Stonehammer]

Level up to 10 (which is when BBs get two extra attacks thus being able to deal significant damage to Astos) and keep reloading until his RUB attack fails.