[lurkingknight]

the SHS is either a gross factory misprint, or you can take into account that you CAN use an over volumed cylinder on a short barrel and it won't make much of a difference. You can still achieve your target fps with more air pushing, you just aren't being efficient about it. In most setups, you wont' run into any weird issues when mismatching. Probably only in the most extreme builds will things like that start becoming factors.

and by extreme, I'm thinking more the 40+ rps setups.

edit:

of course, you can verify what you need by doing the math yourself... buy a full cylinder and cut your own port in it in the correct location to match your barrel volume. the sweet spot ratios are all in a chart out there somewhere.