Thank you all for getting this confirmed M1/M14 guy to see the virtues in the AR.  However, after reading the Canadian Tactical post, replies, high end discussion, graphs, charts, bullet weight, boattail, jelly, yaw rates, etc., etc., well, I'm perplexed over what I see as a simple issue.  You see, if the combined effects of bullet weight, +/- 200 fps, barrel twist between 1 in 7 and 1 in 9, barrel length, bullet design, etc., ad nauseam, are so significant to this round and its performance, then the round is flawed.  The 7.62 NATO round came from efficiently trimming the fat from the .30 and was ground up designed as a penetrating people killer at range if necessary.  The 5.56 hatched from a varmint round, intended to be a light weight survival round, that was forced into the role as a combat round.  This "yaw" thing was post hoc rationale for the purpose of showing that the 5.56 could be a death ray v. the 7.62.  (You know, for once the Brits were on to something in small arms with their .280, but then again, they now have that bullpup joke rifle).  Will the 5.56 drop people out to 300m. and penetrate sheet rock and bits of wood?  Sure it will, but so will my rimfire .22 magnum.  As some of you have wisely reported, shot placement is everything.  The 5.56 will NEVER be a 7.62 just as the 9mm will NEVER be a .45.  No amount of powder, twist, shooting jelly, bullet weight, etc. will ever change that.  I own and use all calibers and recognize their virtues and limitations.  But if you want to surely sit that Goblin down and roll him over cross-legged for good, behind cover, at range, stop his vehicle, etc. without having to fret about Dr. Fackler, shooting into jelly, whether your boattail bullet and fps are ideally suited to the twist of your barrel, ad nauseam, use a 7.62 NATO (or 7.92, or 7.62x54R or .303 Brit. or 7.7 Jap. or .30M2).  I shoot SA military .223 cause its cheap, works, is accurate out of my rifles and I don't agonize over all the minutae.  If Mr.Goblin isn't convinced by my nonstateoftheart SA 5.56 that he's been hit, hurt bad, and needs to stop, well, I'll just have to keep convincing him (the beauty of low recoil and high mag. cap.).  Just my musings and thanks to all for your help in kitting out my AR15's with cool stuff and helping me enjoy my AR's.  I welcome criticism and have a good Thanksgiving!
Cleophis  

Cleophis....well put!  Yes...I am partial to the .30M2 and 762x51 also.  For up close work I like an SAR-1 with the old standby 762x39.  And I also enjoy ARs and shoot a lot of SA & Q3131A 5.56 too.  
Like you said....shot placement does count.

Great, a thread that's one big 7.62x51mm circle jerk. [;D]

Hey.  Play nice.

I too am partial to 7.62, past 200 yards.

Inside, I prefer a 16" 5.56.

It all depends on purpose.  Every round has one.  Don't use a wrench for a screwdriver's job.

No, not at all.  A 7.62 circle jerk would include a condemnation of the 5.56.  I LIKE the 5.56 and AR15 weapon system in its matured form.  I own three AR15's.  You don't need a 7.62 all the time.  It's heavy, uncontrollable in FA, and overkill for soft targets.  If any circle jerk exists it's over bullet wt, fps, twist, bullet design, etc., etc., in an attempt to make the 5.56 everything for everyone all the time.  Newsflash: it ain't and won't be.  Hence my peace with my SA ammo (which may or may not be 200 fps slower than the latest Black Hills wonderloading which costs 5 times more).  Had a nice long talk with an LT from SEAL Team 6 about a year ago.  Out were the MP5's, in were the M4's, but they train with, maintain, and use the M14 and M60.  I agree with that Seal circle jerk logic.