I figure that any modern rifle oughta be capable of sub-MOA groups. The manufacturing machinery is just too good.
Bingo. For instance one of the FFL's that works for Gun Tests Magazine is a friend of mine. I have gotten a lot of good firearms from them over the years. About 3 or 4 years ago, they had a test on synthetic stock .270 rifles, much like the current issue. I bought two of them because I wanted to make a gift of one to a friend. A Winchester and a Savage. The Savage was a little more accurate than the Winchester but not quite MOA - according to the write up. I let my friend choose because I knew I could tweak both of them. He chose the Winchester because of the name (I did recommend the most accurate ammo for him and he still uses it) and I took the Savage.
A little bolt work, stoning the trigger (it was awful!) bedding and I am here to tell you 9 groups out of 10 will be sub MOA with factory ammo so yes I consider that a sub MOA rifle. I don't have to be a gunsmith to 'tweak' a rifle to get it's maximum potential realized.
Its the anal "must shoot sub MOA" crowd that gives me so many deals on the local consignment rack, so far I havent found one yet that wont hit a man or dear size target at 300 yards.
It's the "can't handle the recoil" that has saved me the most money. Besides, I don't shoot men. Carlos Hatcock is considered one of if not THE finest rifle shot of his time. But I take with a large pile of salt his personal rifle would only shoot 2 MOA.
Perhaps when the war was over and it was finally turned in... but not as he carried it every day. He as a 1000 yard shooter and knew the realities of accuracy... a 2 MOA shooter does not allow you the variables to make a shot on an 18" torso at over a mile.
I don't shoot men. I am a hunter. I am not particularly concerned if it will hit a silhouette at whatever distance. I want to know for a fact that it will hit that 'spot' on that animal at whatever distance I have to shoot at. A grapefruit sized target on a deer.... I need to be able to hit that within my capabilities. Hitting a deer at 300 yards doesn't take 1 MOA. Hitting his heart does. I don't take that length of shot unless there is no other choice, but I have. Elk at 500? You bet... I have a basketball sized spot.
Prairie dogs at 500? Darned sure better have a sub MOA rifle to hit those boot sized targets! Every AR I own is sub MOA. Coincidence? Not hardly. I own probably dozen +/- .22 rifles and I have built 9 of them on the 10/22 action. Every one of those will shoot 1/2" or less at 50 yards - with sporting ammo. Not $1 box ammo, but not $10 a box ammo either.
If your idea of accurate enough is 3" at 100 yards, then you probably will restrict your shooting at a range you know you can hit the target of your choice. If you believe 90% of people can't shoot MOA, that is your opinion, but I would venture a wager that that number is far, far smaller for the populace here on THR and on other 'gun sites' because we tend to be the gun nuts.
In my experience, real gun nuts are never satisfied with mediocre accuracy no matter what they are shooting. Just because an SD pistol is 'accurate enough' shooting 5" at 15 yards does not mean I would ever own one. If I can't make my SD arms shoot into 2" or less at 15 yards I don't own it long. The fact that my favored 1911's will do so at 25 with 100% reliability is even better.
So my point is, it is about perspective... what you consider accurate is based on what you shoot, where you shoot, how far you shoot and with what. A Mosin shooting 2" at 100? A 30-30 shooting 3". Great! I wouldn't own them.
That's just not my bag, baby!