I don't think you would be able to shoot the accuracy difference between a 24" and a 20" barrel out of an ar. "Mel" has been posting pictures of sub half minute groups out of his 20" barrel. Ive shot 8 shot groups out of my 12" krieger under .7".
A 20" quality barrel (krieger, bartlein, lilja, proof) will/should out shoot a 24" faxon, odin, etc. Another thought is get the entire larue kit and then swap the barrel only (and maybe gas block tube) if it doesn't meet your expectations.
A 20" quality barrel (krieger, bartlein, lilja, proof) will/should out shoot a 24" faxon, odin, etc. Another thought is get the entire larue kit and then swap the barrel only (and maybe gas block tube) if it doesn't meet your expectations.