I see for myself what any firearm is "good for", whether its an AK, AR, or a 1911, in my hands.
I define it thusly (for me): Whatever range I can dump (rapid fire, sight and squeeze) an entire mag into, standing with sling, and hit a 12" circle with 75% repeatability. Bolt rifles, scoped rifles, .22s, and single shots get evaluated prone.
Sure that means a 7 shot 1911 and a 30-rd AK or AR get rated differently due to magazine capacity, but then again, that's the best I (myself) can do with it under something even beginning to approach a "real use scenario". It's also more realistic IMHO than asking around for what others can do, using different weapons/sights/ammo/etc.
Using that as a benchmark, I find I don't have a whole-heckofa-lot-of "effective range" (range that I thought I did have from reading books or internet posts) with a rifle. The 1911 though has more range than you might think on paper, so that's my "consolation prize".
Disclaimer: I'm not much of a rifleman at all, but a fair shot with a pistol.