In my youth, a 5mm Sheridan pellet rifle was my squirrel go gun. Then 22 short. I did use a 410 once, but I felt it made way to much noise.
I used the same 5mm Sheridan with a scope as a young adult. Put the combo together one night after some sipping whiskey. Took a 4X12 scope off a rifle and mounted it on the scope mounting bracket you had to buy from Sheridan. I had ordered two of them by forgetting that I had the first. Had to alter a scope mount to get the over size scope on the gun. Took ten minutes to sight it in and it was dead on from 25 yards to 40 yards. Use to shoot .410 shells at 25 yards to check zero. Set one up and lay the second end to. If you could hit the first one left and right was good, then shoot the second to check up and down. It was kind of cool having so much magnification. You could watch the pellets in flight and watch the impact. Best shot I ever had was a through and through head shot that hit the second squirrel in the chest killing him. Only doulbe I ever managed and it was pure luck.
That gun thinned out the tree rats for many years until my son took it over. Might need to see if he still has it. I did later take the $400.00 scope off and buy one intended for pellet guns. Vibration kills scopes and parallax can be a problem.
