Mississippi should use the lvl 68 2x 16"/50 Mark 2 Ls I think

They have longer range than the Sevas according to the range chart here in the US section;

http://fm.en.kupaisky.com/Community/Forum/View.aspx?num=8028&searchtype=0&pagecount=0&searchvalue=&sort=5&category=A01&page1=1

dont waste your olives on Sevastopol...it does not pay off: cost a lot of olive that you might consider using for purchasing experts/vets/boost for your crew, back in the day when there was nothing more than EBB1... this was a reasonable olive trade, but nowadays where TNF makes an event every weekend giving away EBBs... it's just silly to get it...

and do not waste an "EBB ticket" on Mississippi. it comes only 2/3 lvls before BB2, it has only the same supports as a BB2 and uses BB2 (dual 16') guns. but if you put the same at-level crew on a Colorado and Missi... the Colorado will run faster. So its just a slow Colorado... something just like a tenny with some more room for ammo... and you are wasting an "EBB" chance that might consider using on a Maryland and Missouri

the combination of Colorado/Maryland its better than Sevastopol/BB3 by itself and Mississippi/BB3... so aim yourself in events for Maryland and use your olives for experts/prem/boost/PCA or something more useful