Mm depends...
At fac velocities, in 177 velocity is vital,. Example :
My Diana 56th although deadly accurate was spiralling /corkscrew ing pellets at 915fps, research led me to Hector J Medina a world champion spring gun shooter and custom gunsmith with extensive knowledge of the 56.He advised 875/880 as the best velocity for the jsb heavies through this gun. I retuned the 56 to exactly this power level, and all spiralling gone, proved by extensive target sessions at various ranges.
The slight drop in velocity did the trick.
So in my experience, if you ask the right questions the research is not a waste of time at all.