I recently picked up a Bushnell SMRS 1-8.5 rimfire scope. Has anyone used one (or a similar magnification) on a .22lr? I’m wondering if it can do double duty as a plinker and for some grouse hunting. I’m hoping that 1x with the dot illuminated will be really effective up close and the 8.5 will work well for picking off heads a little further out. However, I am worried about parallax.
Anyone care to share their thoughts?

I've never heard of grouse hunting with a 22. I've always used a shotgun and have never taken one while on the ground.

With that said, I typically use 1.5-4x or 1.5-6x on my rimfires and can often pull off head shots on squirrels if I do my part.

I don't know why you couldn't hit a grouse with one.

For a good many years I had a 4x fixed magnification scope on a single shot 22. It's not the hot set up that the high speed low drag kids play with, but stuff got killed and young me was mighty proud of my iron. Anyway, 4x was enough zoom without getting too narrow a field of view.

IMO, the rig you have will likely do what you want.