Headspace… do it or not a big deal?

[dave_the_ss]

This is my first ar build. Some guys say do the head spacing others say don’t worry about it…. 
I have a hodge podge of parts. Aero upper, cmmg barrel, and a Grendel hunter bolt. 

Coming from the bolt world headspace is 100% especially for accuracy.
I’m not building a 1000 yard ar but accurate round on target (coyotes,fox bobcat ) are a must