16"....1:8 twist....free-floating handguard (Mlock)Jangle, congrats on your first AR. Like bolt guns they can be addictive. Especially when it's so easy to swap uppers/mags to change cartridges.
I think you'll be happy with RRA. I've had 2 RRA uppers in the past and both shot well. I'm a big fan of their 2 stage Varmint and NM triggers too, have several in different ARs.
Out of curiosity, what barrel length/twist did you go with? Most bulk pack mil-spec ammo does 1.5moa or more so don't let that discourage you, these little rifles can shoot. Factory match loads will get you better groups and since you reload you can get the most out of it.