I weight 185 pounds 6ft . I have really small arms for my streangth left is 14.5 and right 14 flaxed and last nite I benched 315 once. (not complaining about my chest size but my arms make me sad) So is it common to have small arms but bench a lot?
Well triceps are a secondary muscle in benching, although I'd say bench press uses MUCH more triceps than would DB presses.. It's not that uncommon, however a .5 difference between arms would warrant some isolation in the smaller arm especially if your compound movements are advanced enough to bench over 300.. All in all, bodybuilding is always a "work in progress" so just keep at it, correct any problems, and be patient.
BTW congrats on the 315 i'd love to get there someday.