OK, Let’s use an Anschutz as an example. What is different about your buddy’s rifle? Why does his shoot ½” and yours an inch. By the way, to me, an inch at a hundred is very impressive for a 22.
Yes, 1" at 100 yards for a .22 is impressive. Yet it is not as uncommon as you might think, though, when a quality rifle is matched with its preferred ammunition. That takes a
lot of experimentation to find a rifle's most preferred ammo.
First of all, I am not a gunsmith, nor do I aspire to be one. I am not an expert of any kind. I have gathered my meager knowledge over 50 years of competition shooting beginning with NRA 50ft indoor smallbore with a local rifle club when I was 11.
If you lay my Sako P04 next to my friend's Anschutz, there are a few things that immediately stand out. (Keep in mind the Sako P04 is a "Hunter" class rifle versus the "Standard" class Anschutz.) His Anschutz is a competition grade rifle that he paid in the neighborhood of $1,800 - $2,000 for several years ago. The barrel is heavier, his stock is heavier, the overall weight is more than 2x heavier. I know the chamber in his rifle is a match grade chamber and that his barrel is hand lapped and air gauged. The Anschutz trigger is adjusted to 10 oz. and is extremely smooth and consistent. His scope is an older Unertl, but is incredibly clear with a fine crosshair with target dot reticle and 1/8" per click adjustments at 100 meters. (My scope is a 6.5-20x50 side focus Vortex with a duplex reticle; 1/4" per click at 100 yards.)
The Sako P04 is a fine rifle in its own right, but does not have anywhere near the refinement as the Anschutz. But then, I paid less than 1/2 as much for the Sako as he did for the Anschutz. With all that said, a rifle is only as good as the ammunition and even with both of those, rifle and perfectly matched ammo, the combination can only be as good as the shooter.
When my friend's Anschutz is shooting 1/2" groups at 100 meters, it is with his competition ammo that has been culled specifically for his rifle under perfect conditions and he is having a 'best' range day.
When he tested match grade ammo and found the best shooting brand and lot number, he bought a case of that ammunition. It cost him a little over $1,900 for 5k rounds. He then culled them by weight and then again by rim thickness. He netted just under 2k rounds of what he considers match competition ammo he uses strictly for matches. The rest is practice. And he practices a heck of a lot! He says a case of ammo lasts him almost 2 years.
I hope this is helpful.