The first problem was that you were using a Ruger 10/22...should give you about 2.5"-3" groups at 25 yards. Ain't quite minute of squirrel.
But yeah, taking the time to bench-sight 'em in would help
Winchester's aren't famous for their precision either...it's part of the reason they went out of business since Marlin made more precise lever-action rifles since the 1940's. Check the winner's circle at any SASS meet

Won't find many Winchesters...but you will find Marlins. Even Mossberg makes a better lever-action than Winchester ever could.
There are things you can do to help both be more precise...I'd stick to the inexpensive/free mods because it can get expensive real fast. You can EASILY spend $800+ on trying to bring a Ruger up to snuff...but it'll never be worth what you put in it. Kind of like Putting a Turbo-charger in a Yugo.
Check the Winchester forums & Ruger forums here, & proprietary websites (RimFireCentral (Ruger)) (Winchester Owners)...that sort of thing.