Sorry guys but anyone who still thinks 200 fps matters in a straight wall handgun case just doesn't yet understand how and why they work. Both myself and Lloyd Smale have been trying to explain this to folks here for years and it seems folks still don't get it. Read the thread about light bullets, I think it's on the hadngun hunting forum. Energy as it relates to this discussion is a non issue, it's all on paper and not something in the real world.
GB
Either I misunderstand you or you misunderstood me, not sure which. As an archer, I firmly believe in the slower heavy arrow for complete penetration. I also believe the same applies to bullets, one reason I rebarreled my 30-06 to a 338-06, to sling heavier slugs.
That said, I feel it's always nice, if you can, to fling the heavier arrow (or bullet) as fast as possible, as long as it is accurate. I know there does come a point of diminishing returns, just like in archery, as poundage goes above 60# the return for energy delivered is less as the poundage goes up.
Wouldn't this be like the case of the 44 Mag vs. the 445 Supermag, or to the extreme, the 444 Marlin? There IS going to be a gain in energy, and trajectory, but at what point does it become a gain of diminishing returns? Is this what you're meaning?