.177 does over drill at close range. I find the dropping power increase the further away the quarry is 3specially against certain quarry like woodies.
I switched to hollow poi t for closer stuff and a lower power rifle in .177 will also help.
If it is dedicated to barn or close range ratting I would definitely consider a .25 ove4 a .22 but I do little so I just rely on didstance and the hollow points.
In a battle of wits I refuse to engage with an unarmed person.
To one shot one kill, you need to seek the S. Kill only comes from Skill