Can upnorthairgunner explain barrel length vs power to us

[Long_Gun_Dallas]

Jesus christ. I feel the need to huff some silver paint to get on this level 

 

[Bobbybeef]

I went from a 300 mm to a 500 mm barrel on my fx compact which is not compact anymore and the FPS went up 110 FPS higher air has a longer barrel to push through before the inertia of the air leaving the barrel which means higher velocity 22 cal went from 23 FPE to 32 FPE which means when i hit starlings and sparrows they explode