Accuracy reports for the 15-22 vary greatly.
I've worked with mine quite a bit.
First fluff & buff on the FCG (wasn't happy with that), changed the hammer/trigger springs with JP reduced power springs (wasn't happy with that), and finally replaced the FCG with a CMC 3.5# drop-in FCG (VERY happy with that!).
I also spent a lot of time with a lot of different ammo, trying different brands, velocities, and bullet weights until I found the one that produced the best accuracy - most consistently.
It's probably just a coincidence or just in my mind, but I installed this hideous compensator I picked up at a gun show for $12 on and I swear it shoots tighter groups with it on vs. the standard A2 flash hider.
Lastly, I put a quality optic (one with a parallax adjustment) on it (Nikon Buckmaster 4.5-14x).
I know the rifle is far from stock configuration, but I can consistently get 1/2 to 3/4" groups at 50yds and 1.5" groups at 100yds.
Not everyone is willing to 'tinker' as much as I did or install quality components costing as much as the rifle itself to get something they are happy with. I did, and I'm now more than happy with this rifle and will put it up against any 10/22 or comparable range bolt action rifle within a reasonable price range.
Unless you get VERY lucky and get an exceptional 15-22 with an above average stock FCG, your skills are far above the average shooter, and you pick just the right ammo right off the bat, you are unlikely to get 'tack driver' performance from this rifle out of the box.
The stock AR platform was designed to hit the center mass of man sized targets ranging from 50m to 400m and was never designed to produce competition sized groups from soldiers. Many folks buy the 15-22 or a stock AR and expect more from them than they were ever designed to produce. The triggers and sectional design of the AR platform are at odds with pin-point performance.