I have a personal AR that I built as a general purpose "fun gun" that could also be called upon in an emergency to perform defensive duty.  I'm looking for ideas on a cartridge that can do several things (rifle is 16" 1:9 twist); some of my desires include:

* 1 moa or less to 300 yards (I know this can depend on gun/shooter, but read "known to be generally 1 moa from most guns")

* not excessively penetrative yet still capable of penetrating auto glass (while not needing to retain all of its weight, it should retain enough to inflict damage after penetration)

* capable primarily against coyote and deer (not to mention the occassional terrorist that may stop by to visit)

* not terribly expensive (I know, subjective)

Does such a load exist?  If not, is there anything close?  

Some loads I had considered were the:
* Winchester 64 gr power point/soft point     - I have heard it is not very accurate?
* BHA 68 gr otm                                         - will this hang together through glass, too explosive on   deer?
* BHA 60 gr soft point                                 - I don't know much about this load?
* BHA 60 gr Nosler Partition                         - too expensive?
* Fed 55 gr TBBC/Tactical                           - I think this may be too penetrative, though ideal for deer and autos

Can anyone offer any credible advice?  

Go to the Ammo Oracle.

I think you have missed my point.  Perhaps that is my own fault for not explaining myself well enough.  I am not looking for some magic bullet that can do it all.  I am looking for a round that is a compromise.  

As an example, the otm's are great at fragmenting to increase and assure wounding, while the Federal tactical is perfect for penetrating obstacles.  For work, I carry both loads and choose which I want for my mission.  When I am "off" and cruising around my property or around the area I live, I don't lug the same amount of gear with me and I don't want to carry several magazines loaded with different projectiles.  

I suppose what I am looking for is a bullet that will not explode with a high percentage of fragmentation on thin skinned game yet does not excell at penetrating hard obstacles with 100% weight retention either.  Should I ask my questions thus:

1) How much penetration, expansion and wt retention / % fragmentation does the BHA 68 otm give after penetrating auto-glass?
2) How much penetration, expansion and wt retention / % fragmentation does the BHA 68 otm give after penetrating auto body sheet metal?
3) How much penetration, expansion and wt retention / % fragmentation does the BHA 68 otm give through a deer?
3) What is the typical accuracy people are getting from BHA 68 otm?

Repeat the questions above for BHA 60 gr soft point and Win 64 power point/soft point.

Does that help?

ETA: I have looked at the Ammo Oracle before, however I went to it again and see that there is a lot of new stuff there.  I didn't realize it was a "work in progress."

I think what Troy was saying is, you have to make your own compromise. You are going to give up a little of this to get a little of that. Only you can decide which to give up and which to get. There is no round which gives up a little of all of it, in order to get a little of all of it, which is what you seem to be looking for.

If I were to pick a load given what you have said I would choose the Win 64 gr power point. It works great on deer (which is my primary motivator) I feel that it will penetrate auto glass and I am sure all or most of the lead bullet will be inflicting damage, maybe not in one piece, but I can assure you If I am shooting into an automobile there will be MORE THAN ONE shot on it's way! (can we say FULL AUTO!)

Accruacy? Well just have to try it and see.

+1 on the 64 grain power point. i believe it is one of the better choices based on your requirements. if your gun is reliable with them than you are good to go and by the way these shoot about .5 MOA out of my Colt HBAR ELITE.