I've got tons of gophers digging holes in my yard and under the garage. This year I bought a Crossman P1377 and was told you couldn't improve the sights on it. Well, I found a picaninny rail for it on EBay and put a red dot scope on it and so far 7 gophers and a huge 2 lbs. mama squirrel have fell to it.

A nice choice for a backyard varmint thumper. Variable power and they are easier to shoot than a springer pistol (less movement)
The light weight PBA pellets are a good choice for a gun that doesn't make a lot of air power and they do penetrate!
Which red dot did you pick?

Didn't spend much but this is a super good sight for the money.

https://topairgun.com/product/utg-30mm-red-green-dot-sight/

Shooting Gamo Raptor .17 pellets. Since I put this sight on I'm 3 for 3 on gophers. Total is now 8.