JB,
If this is your first time casting with a Lee 6 cav mold, I'm gonna guess you may be "gripping" the Sprue plate handle against the other handles. The Sprue plate handle/lever has a cam, if you apply pressure, so the cam is pushing against the mold, that may open the blocks a tiny bit, and give you oblong boolits about the size you are describing.
Most of the time, a Lee 356 mold will make a boolit .001 or .002 larger...So you .358 size is about correct, but the other dimension shouldn't be .362 If it is, and you are gripping the Lee mold correctly, then I'd consider returning that mold to the vendor, becuase, Ideally, you don't want to size them down more than .002 or .003 at the most...and since you water-dropped them, sizing a .362 oblong boolit down to .358 will be a chore.
Jon