So I know there is a dif. between 5.56 and .223, but what do most people on the AR platform prefer? Im also trying to get into reloading, so if it is the 5.56 what do I need to know about reloading a 5.56?

It depends on what chamber your barrel has. It should be stamped on the barrel someplace which chamber it has.

You need to know that the Reloading Forum <---- is over here.  

and, I am not sure what difference it makes which others prefer, but

the Ammo Oracle <--- is over here.

I own a windham and I its a 5.56. What I want to know is if there is a clear advantage to shooting a 5.56 over a .223 (I again, save my brass for reloading and I get mixed readings on reloading 5.56)

5.56 is usually loaded a bit hotter. M193 will have higher velocity than a 223 load from the same gun. I shoot cheap 223 junk for plinking and some training, M193 for some training, and the BH 50 gr TSX load for serious bidness. For defensive use I'd suggest 5.56 as your rifle is chambered for it, for shooting dirt clods buy whatever you want.

The brass is the same

I have all 5.56 chambered rifles, but I load .223. Doesn't matter if you have 5.56.

I don't trust reloads with my life. I buy quality factory SD loads.

I prefer 5.56 but I do more tactical shooting, it allows higher pressures and a 5.5 chamber can shoot .223 as well but a .223 can't shoot 5.56. People who shoot bench rest typically prefer .223 tho

The 556 case spec is sloppy, so as far as your reloading is concerned, size all cases to .223 specs.  Then load to 223 specs if your rifle is specified as 223.  If your rifle is specified as a 556x45 (and it probably is) you can load a little hotter to 556 specs.

If you are loading for economy, this is all you have to know.  With a little care, your handloads will be far more accurate than any non-match-grade ammo you can buy.  If you are loading for peak accuracy, however, don't resize your cases at all - let them be fire-formed by your rifle, and only resize the case neck.  You will likely have more accurate loads in the 223 range, and I think that the heavier match bullet loads are 223 pressures only.

alright thanks guys, ill just get 556 and reload to .223

My ARs all have Wylde chambers which means that they can shoot 5.56 and .223 like all ARs but the Wylde throating allow the rifles to shoot .223 ammo with great accuracy.

I have a bunch of 5.56 for SHTF stuff but I use .223 for all of my "fun" shooting and working up loads for " bug shoot in'"

My ARs are scary accurate with 55 grain Blitzkings and 24.5 grains of 4895 in .223 cases.