I have shot sub MOA groups with several rigs having 4X.
Back when younger I did it with iron sighted rigs on bags.

But I'm older now, eyes went to crap.

Shooting last week at 50 yards, I was wanting more than 7X on my .22lr.
My #1 RSI .243 wears a 4X. Did OK, but it's just for deer. Heading out in a few to check it at 100yds.

Ideally with the crappy quarter rib/ring game......it should wear an older longer tube VX2 2-7X. But I got the 4X at a decent price.

As a kid, I repeatedly shot groups around a half inch with a 3-9X cranked up (at 100 yds). My old #1B (jr high) shot as well as my prev 660...9X.

Nowadays I couldn't imagine a dedicated chuck rig limited to 9X. Had a AO compact on another 600.......and it did .75" but there again, at the range.....I was wanting a little more. Kid didn't want to deer hunt, so I sold that rifle. Like a dumbarse.