Tuning First time with a non PCP and need an advise

[bigHUN]

I am doing my backyard - property damage protection - temporarily with my .22 Leshiy2. This was my least power option safely doing the critters control in the backyard.
But I want my L2 back to my gun club games.
A friend offered me he's Daisy 753S Elite I can use as long I wish.
I got it to my hands, this thing looks like a plastic toy, also with a sub 500 I am not sure what I can do with it around my walnut threes.
Any tips I can boost it to some decent knocking power level for squirrels?
I cannot justify buying a non PCP for backyard short distances....I am talking 5-10 meters and mostly up between branches.

 

[beerthief]

I am doing my backyard - property damage protection - temporarily with my .22 Leshiy2. This was my least power option safely doing the critters control in the backyard.
But I want my L2 back to my gun club games.
A friend offered me he's Daisy 753S Elite I can use as long I wish.
I got it to my hands, this thing looks like a plastic toy, also with a sub 500 I am not sure what I can do with it around my walnut threes.
Any tips I can boost it to some decent knocking power level for squirrels?
I cannot justify buying a non PCP for backyard short distances....I am talking 5-10 meters and mostly up between branches.

yes it can be done easily, but you might have to take 2 shots to kill . up into the brain through the under jaw shot would be best , maybe a 8. 64 grain H&N FTT pellet ?

 

[SteveV]

Why can you not justify?

EDIT: meant as a response to the op

 

[bigHUN]

Looks like I will give up on .177 idea entirely.
The 15gn hades at 750 fps (detuned L2) will render the critters obsolete with a single shot to a highly visible vital zone.
Up through the branches the clear headshot is less then 50% most of the time.