[Dionysusigma]

Are there major deciding factors in the accuracy and reliability of a gun? I know that as far as tolerances go in general, tight=accurate and loose=reliable.

However, I'm wondering if a heavy-barrel AK chambered in 5.56/.223 with a 3.5 lb. trigger would provide comparable accuracy to a HBAR AR-15... and if not, why? Assume ergonomics, weather conditions, lunar phase, etc. are identical.

[blowback]

and the issue iron sights and trigger pull.

[Destructo6]

You're talking about clearances, not tolerances.

A "tolerance" is how close a part adheres to the dimension(s) given on the print.

A "clearance" is how much space is allowed between parts on the print.

Such as, a very tight clearance (.001") provides a press-fit betwen parts. If you screw up the tolerances, that press-fit could become a slip-fit or simply impossible to fit together at all (going the other direction).