I have found a used Colt SP1 in a local gun shop. It has a 20inch barrel, flash hider, bayonet lug, no mag fence and an A1 upper.
As I've never bought a used AR or owned a Colt what should I look for or avoid?
It looks like it has screws connecting the upper and lower reciever, can these be changed out with the push pins?
What would a reasonible price be for a SP1 in 90-95% condition?
Thank you for the help.