Most of the ability to hit a target is in the rifleman and not the rifle.
Yeah the Mini-14 is a 3-5 MOA weapon which means that much beyond 300 yards it's hard to consistanly hit an 18 inch rifle gong - that was the size of my gong - which is the size of a man's chest from the belly button up. Of course out at 300 yards it's aweful hard to see a man sized target expecially when that target doesn't want to be seen like wearing camo and taking advantage of cover and concealment. I live in a built-up urban area, the only time I can see 300 yards is when standing in the middle of the main streets, highways, or standing on the roof ... all are the last place you'll find me or a target when the shit hits the fan.
Many burglars do not rob the house from 300 yards away. Most assualts occur within 300 yards. If you're using a rifle to defend yourself its going to be inside of 300 yards - more than likely inside of 100 FEET where the Mini-14 can put rounds into a golfball.
Of course the rifleman has more to do with the accuracy than the rifle. Most people can't hit an 18" rifle gong at 100 yards freehand - that's standing. Many can hit that target while they're prone ... but some can't until coached. Kneeing/sitting somewhere in between.
One of the best things about living here in California is the massive amounts of BLM property where it's perfectly legal to go out and practice some tactical shooting. I have two 18" square rifle gongs and one 12" gong. I'll hang these from make shift stands (as the factory stands have long ago been shot to shit) and set them up in a pattern against a hillside out in the desert. I'll then drive my car out away from them measuring a 150 foot point and marking that area. I'll then walk out to 100 yards or so and start to engage the targets doing rapid pairs of hits on each while standing. I'll walk around the desert assuming different stances and light the targets up off hand. Then I walk out away from the targets and continue to ring the gongs - I continue to walk out "learning" with my eyes and my rifle what I can hit at that unknown distance from standing. I'm calibrating my eyes to see 18" and know if I can hit that target on the first shot or not.
Eventually I get out to 150-200 yards and it gets hard to promise a first time hit on the 18" gong - that's 12 MOA if you're doing the math - and I go "rice paddy prone" kneeling and repeating the same exercise of ringing the gongs back and forth. My knees ain't what they once were and then I go to USMC style sitting. I'll move about shooting around and over rocks and brush.
Finally I get beyond 200 yards and need to go prone to get my first shot hits. Depending on which weapon I'm practicing with I can end up 600-800 yards away before I have to return back. Out at 400-600 yards it gets hard to hear the gong ringing and there is a big time delay between bang and ding. Only with electronic hearing can I hear the gong's ring that far away. I'll cut over 30-45 degrees in one direction or the other and work back toward the gongs with different terrain and different lighting angles to worry about again calibrating eye and rifle to hit the target with the first shot.
Out at 800 yards it takes a bunch longer to hit the target prone than at 200 yards as I have to adjust the scope for that range and scope depending that means counting clicks or dialing up a BDC.
I might get two rounds of training like this in a morning or afternoon practice. I like to do one following sunset where working the scope in the dim light is difficult.
The whole idea is to get off the dang rifle range with its 100.00 yard range, concrete benches and seats, and shade. There is nothing special about my drills and what ever works for you works. I do highly recommend steel gongs as a training aid as the instantanous feedback of the ringing re-enforces good actions. Trying to read paper holes at 200 yards without a spotting scope isn't easy. For my needs a hit on any part of the gong is a bullseye as I don't care where at you hit a man between the nipples, bellybutton, and collarbone you're going to make his day with a .308. In my book even a 62 grain .223 isn't the right round to engage human size targets much beyond point blank range (225 yards) and it's time to pull out a .308 which will do double that with a 168 grain boattail.
The 12" rifle gong is my "head shot" (not that I've seen many people with a 12" square head). I'll take a cardboard box and use rocks to set the box to obscure part of the smaller gong to simulate a person shooting from behind a hostage or cover. I then have to shoot the gong while avoiding the cardboard which records each miss.