RE: AR15 varmint??
If you want an accurate .223 why not a Tikka bolt? They are shooters!
If you're stuck on the cool look (I am sometimes too) then check out the Olympic arms from Washington state.
The ultra match model is guaranteed to shoot sub-1/4" at 100 yards. That's impressive! Their site is olyarms.com
I think the ultra match is at the very top of the page.
The Olympic rifle evidently out performs the Les Baer .223. That too is impressive.