I have an older Windham made Bushmaster and love it for accuracy and reliability, You don't need forward assist on a 308 believe me the last thing you want to do if something is wrong is jamb the shell in there tighter. Dust covers are nice. Check warranty on all, S&W and Colt has very limited warranty I was going to get a Smith because it was cheap, But in trying to contact them 4 times by e-mail they always mailed me back and said they were busy right now and would get back to me. That was over a year ago still haven't heard from them, Colt is a 16" with a 1-11 or 1-12 twist good if you want to hoot 147 grn ammo, I like a 18" - 20" on a 308 with a 1-10 twist
Colt is also very proprietary on their rifles.
If you are in the price range of Colt check out Sig 716 it is also very proprietary But they do have trigger kits etc the Patrol is reasonably priced I went with the SIG,DMR 18"- Match grade barrel. Piston Driven, 2 stage Geisel trigger . Life time warranty if it breaks they fix it period, Good CS