That's what i was leaning towards even though I'm a lefty. What kind of groups do you get with 52-55gr fodder? 
I don't reload .223, so with federal bulk ammo I'll get about average 1.5" groups @ 100yds.  occasionally I'll get a sub-MOA group but that's not the average.
my .223 is the regular American rifle, thin tapered barrel.  like Inspector pointed out, it gets hot after a few rounds and POI drifts some.  
the Predator and Ranch rifles have a "medium heavy" barrel.  not quite a bull barrel, but heavier than their regular tapered barrel 
I bought the rifle to be a range plinker I could use cheap ammo to shoot and is easy to clean and maintain, and shoot at least decent groups 
that's why I got the Ruger American rifle
you might also consider the Ruger American Ranch rifle in 5.56
I think the Ranch is the only American rifle chambered for 5.56, all the other Americans (the Predator included) is in .223