Hello, I am finally building my first AR and I've been offered either a Colt LE6920 or Colt 6720-A3 Upper to go on my lower with a RRA 2 Stage NM trigger. I've heard that the pencil barrel of the 6720 is prone to heat fatigue but I am skeptical of the validity of AR15.com overall. It's about a $50 difference between them so price is irrelevant and both are new and unfired (The 6720 has been in storage.) I'm looking for recommendations because I likely will only have one for a long time. I am looking for a range toy primarily, I know neither of these is a precision rifle but I would like to stretch it out to maybe 300 yards.
Thank you.
Thank you.