The difference between a G27, G23, and even a G22 is pretty insignificant really. I think you're over thinking this a bit. Whatever load gives you the fastest speeds with a G22 will also be the fastest with the other 2.
This is really more of an issue when comparing revolvers with 6-8" barrels with 2-3" barrels. Even then the same loads that are fastest with the long barrels will be faster in the shorter barrels.
Probably the best advice is to note that heavier bullets will probably be more effective if you have to shoot a shorter barreled gun. In 357 revolvers a 125 gr bullet running 1400-1500 fps is pretty effective, but that bullet weight is far less effective a 38 special speeds from 2-3" barrels. The traditional 158 gr bullets are a better choice here since they rely less on speed to get their performance.