there's nothing inherently wrong with using an overvolumed cylinder. The side effect of it will be some slightly higher velocity using heavier ammo... so if you clock at 400 with .2s, technically if everything was properly matched, you should see about 327 with say a .3 but it will actually be a little higher.
Your gun will not explode.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.