Design - Depends on what it's for. SKS was designed for aimed semi-auto fire. AK was designed for select fire. Losing full auto as a civilian kills the AK's biggest selling point to world militaries of the time. If you want to blast as fast as you can pull the trigger, the AK will do it and beg for more. The SKS is better for aimed fire. Doesn't have to be slow, but if you fire faster than you can aim you'll heat up pretty dang fast. SKS is also bigger and heavier for its capacity and bullet energy. So if you want a lot in a smaller package, get the AK. SKS is probably the better choice for hunting due to its profile and small mag that doesn't protrude much and is easy to trim or block. If you want detachable mags, get an AK. If feeding from strippers is fine, the SKS is good.
Accuracy - The average SKS beats the average AK. But the best AK beats the best SKS. Expect 2-3MOA from an SKS, 1MOA from the best of the best AKs (Bulgarian milled and Russian VEPRs on a different pattern and friggin heavy), 2-4MOA from the mid range of AKs (Hungarian, Bulgarian, Russian, Polish stamped) and 3-6 MOA for the lowest varieties (Egyptian MAADI, Norinco stamped, Romanian).
Dependability - The SKS is pretty dang good, unless you find a used up screwed up one, which you still may be able to fix. The AK is much better though. Loose tolerances and powerful cycling make this among the most reliable in the world. Dip it in mud, run it over with a truck, it'll still work. A jam in a standard caliber AK is cause for shock.
Cycling - SKS feels smoother, the AK has a much heavier, harder cycling bolt carrier that you will feel moving inside the gun. The lightest AKs feel like they have a mind of their own. I find this very annoying. Thicker receiver models and milled ones are much better in this way. An internal recoil buffer helps too.
myarmor said:
My friend has a russian SKS that he sporterized
Heresy! Russians are the most valuable and collecticle SKSs out there! Sporterize a Norinco or a beat up Yugo (not a good Yugo).
What do I have? Both, of course. I have had two SKSs and four AKs. All are good. If you want to add a pistol grip, detachable mags, non-compact scope, and other stuff, buy an AK, that's an order... don't butcher an SKS, at least not a military one.