I'm an accuracy nut too, But, though I do not compete I still take great joy in shooting tight 5 shot groups. I don't try to fool myself or others with 3 shot groups, or one lucky 5 shot group. I need consistancy to know it's real. I shoot this kind of sub 1/2" MOA consistancy with the my 2 custom barrel bolt action rifles fairly easily. (1/4" and 3/8" 5 shot groups are not unusual) But, I'm honest enough to tell you that I've had no such luck with my AR platform rifles in either 5.56 or 308. Yes, on infrequent occassion I would get 3 or 4 shots in 3/4", but never the full 5 shots..I can't figure out if it's just that I'm not mastering an AR rifle yet, or, if I've just got bad luck and have been getting stuck with mediocre factory barrels on my stock AR rifles. I got rid of my 24" LR Panther fluted stainless 308 rifle barrel. It would only shoot 5 shot 1" groups on it's best day. Most groups were 1 1/4" using very precise handloads, a fine trigger, and a good quality 6x-24x Elite scope. I recently replaced that barrel with a Fulton 18.5" barrel, and found that barrel shoots no better. I made the mistake of believing Fulton when they advertise this chrome lined Krieger Criterion barrel with the statement "No loss of accuracy with our chroming process". I gravitated to this Fulton 2 1/2 lb barrel because it is black, light, and has an AP4 proifile that would accept an A2 front sight post. While I realize a 2 1/2lb barrel is light and can overheat causing accuracy loss, I only desire one good accurate 3/4" 5 shot group from a cold barrel to smile and know I have one special rifle. I have yet to get that kind of accuracy. It's just my preference to try to keep my AR rifles on the light side and resembling a handy combat weapon.
Maybe you'll have better luck then me, but I was never able to find anybody here to provide any real input about precision target shooting. I'm so tired of reading the general/vague 1 or 2 sentences posted from the kids and the blasters about how accurate they shoot their 308 rifle. If I had 1/2" and 3/4" groups that were the norm out of my stock rifles, you could bet your ass that I'd be posting the pictures on ARFCOM without anybody having to ask me for proof!
(3 shot groups are bullshit and often just luck. I've had plenty of theose too)
If the weight and configuration of a Krieger barrel doesn't matter to you, I'm sure that it will deliver much closer to the kind of accuracy you're looking for. Just be sure to have a bolt matched to the chamber. Let me know how you do. I'm contemplating buying another Fulton...... this time their stainless non-chromed.
barrel.