I don't think you saw my post directly preceding your first.
What we are talking about is the difference between funneling high temperature gas back through an additional system, with the associated delay, in order to cycle the action -- versus direct cycling of the action. The simpler and more consistent action is definitely the blowback. This is why it is successful in both full automatic weapons and highly accurate semi-auto sniper rifles.
Originally Posted by blhseawa
Regardless of the locking system, the bolt release is a function of the bullet passing the point in the barrel where gas is vented back to bolt carrier which causes the action to unlock. Actually, strictly from a engineering point of view the stoner design is better as the moving mass is inline with the barrel. There is torquing effect that interferes with follow-on shots on the HK-91/PTR-91 and the AK-47.
Actually, you've got the engineering backwards with regard to the Stoner M16 design and the H&K. The H&K bolt is direct and in-line, it is the Stoner design that twists to lock and unlock and vents gas back to do so. You do realize that the H&K does not feed any gas back? That's why it is a blowback design and not a gas design.
From your reply, I can see you don't really understand how roller-delayed blowback works, nor the M16. I made a simple explanation earlier.