.223 pressure Gold Dots from a 14.5" barrel

[ABNAK]

The fact that they are .223 pressure and not 5.56 NATO kind of bugs me. I saw Molon's thread where he chrono'd the 64gr GD and it got 2588fps average from a 14.5" barrel. Since most of my AR's have that length of barrel that is what I will base my decision on.

I ran a ballistics calculator with the 64gr's BC of 0.27 at 2550fps. If the velocity threshold for expansion is 1800fps then you *should* get it out to ~ 210 yards out of a 14.5" barrel. Sound right? Certainly not stellar but doable I guess.

*If* I order some Gold Dots I'm leaning towards the 64gr pill. It would seem that the 75gr would be handicapped by an even lower MV and therefore hit the 1800fps threshold way sooner than 210 yards.

My current go-to for my AR's is Mk318.

One more question: how is cycling in guns set up for 5.56 NATO rounds? Some of my AR's are mid-lengths and a couple are carbine length gas systems but all have H2 buffers. Standard springs (i.e. not Sprinco's or such). Two of them have LMT Enhanced BCG's. Need to change anything by going to .223 pressure loads?