I missed that... but I have to say, I completely fail to see the point... .25 I just about get, certainly at FAC 20 FP... but .30 on 12 or even 20FP springer !?!??!
A .25 will weight anything from 19-25 grains, what do .30 start at, 35 grain ? so at 12 FP, that's about 400 fps ! even at 20 FP, it's only 500 fps