I just bought a Armalite M15A4(T) I'll have to say it's the best damn rifle I've ever owned.

I've tried a few factory loads 55 grain SP Blackhills ammo and 55 grain FMJ.  The soft points shot A lot better then the FMJ.  I've been sinking them in just under 1" at 100 yards.  The FMJ's shot bad about 3" groups.  I bought the factory loads because I was in a pinch and couldn't get some reloads done before my trip.  

I know all guns have different appetites but can someone get me close to a good load.  

Including:
What kind of bullet and grain.
Type of Primer.
Type of Powder and Grain.
And what FPS I can expect with a 24" barrel

Again it's a 1:8 twist.

Why not go consult a Sierra Reloading Manual and check for the accuracy loadings for the bullet wt. in question.  As always what is safe in one gun might not be in yours.  So the prudent thing is to do a bit of leg work for your one health and safety.  My guess as for the powder to use would be VARGET. For 69/75/77/80 bullet offerings from Nosler, Hornady, or Sierra. Primers that seem to work well, I would stick with RP 7.5's with Varget.  Brass, I like WW, Military sorted by head stamp is okay.

And, only a chronograph will give you accurate results of velocity. It will open your eyes!

Not what you wanted to read, but hey let's all be safe with reloading!