Well, I am still waiting for my PS90 (not available here atm), but I shoot many other guns, when I have time to do so (at least twice a month).
I usually shoot in the indoor range at 25 or 50 Meters, which is quite easy to get good results with almost any gun.
When I shoot at the outdoor range, i usually shoot my SIG 550 (Standard military issued here) with Ironsights at 300 Meters, and I usually group within 10cm (about 4 inches). I also have other rifles I shoot at these distances, and some only have Ironsoghts. Surely, I can't shoot my M82 with Ironsights only, but that is another type of weapon.
As far as it goes for me, any gun I have, should reach some point of accuracy.
- Pistols and Revolvers: at least 4 Inch groupings at 50 Meters
- Submachine Guns: 4 to 6 Inch groupings at 100 Meters
- Assault Rifles: 2 to 4 Inch groupings at 150 - 200 Meters
- Swiss Army Issue Rifles: 4 Inch groupings at 300 Meters
- Sniper and Precision Rifles: 1 to 2 Inch groups at 300 Meters, decent groups at 600 Meters and more.
- .50 BMG: 4 to 10 Inch groups at 1200 Meters.
That's what I expect from my weapons, and therefor, I usually select them carefully.
Any kind of aiming aid on a Pistol, Submachine Gun, or Assault Rifle, is only to help you to get faster on your target, but never to get better results with your groupings. It's just an aid, but you still habe to aim yourself.
regards
Reaper