I have generally found that once I get under 2" groups at 100m I can't reliably improve the situation.
However, I have generally been able to get my M14s to CONSISTENTLY group around that size, which I think is pretty good.
I like to put a lot of bullets in the target to establish the group. Anyone can launch 3 bullets and fluke a sub-moa group. It is not possible to fluke a 2", 50 shot group! Even 10 shots is starting to give you a very good idea of what is happening out there. But 3 shots is just guessing...if you don't believe me, lock a rifle down in a rest and fire 20 rounds. I guarantee that at least 3 holes will be touching! If you shot those three in a sequence and nothing else, you would think you had a 1/2 MOA gun. But when you run the other 17 through, your real group becomes apparent, and if you can keep that group to 2 inches, you are doing pretty well IMO.
So I would say 2" or under is pretty damn accurate for one of these. But then I am talking about ACTUAL accuracy, not e-groups!
One problem with 2 MOA guns is that they are not as accurate as what a lot of internet shooters own. Most e-guns are sub-MOA, which makes a true, real life 2 MOA gun seem kind of lousy.
But remember that an e-gun is measured differently than a real gun...a 1/2 MOA e-gun is roughly equivalent to a 6 MOA r-gun.