I think whoever started this thread was interested in certain tweaks, mods, replacement parts, etc. that could be accomplished by more typical, "standard" AK owners.
I'd love to hear something on that level.
well if were talking about a standard stock barreld AK 47 in 7,62x39, then you are limited to a few things. the big three IMOO are trigger, sights/optics, and ammo.
I recomend the Red Star adjustable trigger as a decent drop in a set up. with out a decent trigger there is no way to shot a really good group unless your really good and spend a lot of time shooting that gun. the AK trigger or the tapco or other aftermarket trigger that are made to meet 922 compliance laws not really improve any thing are pretty bad. they can be worked but its a balancing act and it takes a lot of trial and error. polishing the the mating parts on any of them will help. you got to get a decent scope on it that is powerful enough to take the guess work out of things. I use a 18x or 25X for target work and load development. Its way to big for any thing else but once I gat loads developed I go back to what ever is aproperate to shooting conditions. but for shooting groups bigger is better. A 3x9 will work out pretty well and is a good compermise. on my deer stand pistol I have a weaver 3x its alll I need. the scope mount is a tough call most of them contact the reciver in some way the reciver flexes and kills accuracy by affecting the point of aim. If you go with a side mount get one of the good ones not the $25 dollar ones. skip the dust cover mounts. ther are some that go from the RSB to the stock tang that are said to be decent.
ammo is critiacl I load as close as I can get the bullet to the rifeling and still fit in the mag. in most/likely all AKs you are still a mile from the rifleing. there might be some advantages to loading longer and feeding by hand like I do with the 77 grain 223 loads I use for long range.
I hand load I am hoping to get some 220 russian brass and blow it out to 7.62 this is pretty extream and expensive. the heavier bullets some times shoot better. there are some 150 grain stuff out there try Graff and Sons. they also have a .310 125 grain Vmax that shoots pretty well. the chamber of the ak is really loose some have over .013 neck clearance and the rest is pretty bad. thicker necks or a tighter chamber would really help. If you rebarreling get a reamer that is made with tighter specs.
remove the cleaning rod, mess with gas tube tension try shooting it with the fore grip removed. my most accurate stock barreld x39 is a 12.5" barreld AMD 65. it has a super tight gas tube fit it takes plyers to lock it in. I suspect the short barrel and the tube supporting it is not getting a lot of whip. I have no proof of it but it does shoot better. I have seen the video were the AR is the suber weapon and the AK is total junk suported by BS facts but the slow motion video does show a tremendous amount of barrel movement from the GB forward. Ive tried various muzzel attachments and the AMD brake seems to be as good as any.
if you really want to gain much with a longer barrel then you need to get a heavier profile barrel . krebs sells a GB that will take a barrel just over .750 for around $50 a slower twist would work better. the 30 bench rest run much slower than the 1-10 or so that the AK has. really dont need a twist rate that will stabelize a 180 grain bullet in a AK. a 1-12 0r 1-14 or even slower might work with the 125 grain bullets. might pick up some speed and loose some pressure as well. going to a .308 bore is a good idea but a reamer with a throat made for the smaller throat OD. if you set the neck clearance tight say around .004 on factory .310 ammo it will be about .006 on a round with a .308 bullet seated in it. you can shoot .310 ammo in a .308 bore but will raise the pressure up. loading with 308 bullets give you many choices.
a rebarrel can be done for under $200 or if you do the work your self.
I have done a few with bolt action take off barrels like from a model 700.
30-06 barrels are pretty cheap just cut the of and rechamber. Of course there is not much treally great about a remington barrel. i have a Dougless barrel on one that shoots pretty good. pricy but it accuracy is not cheap. the savage barrels seem to be the better choice of the take off barrels you st Im doing a build on a Howa barrel currently.