I faced the same dilemma when buying a DPMS LR .308. I ended up with the 24" since it will primarily be a benchrest and prone silhouette gun. But to get to the point, I was at the range the other day next to a guy with a Rem. 700 w/24" bbl and one with the 20" bbl. We ran all three guns through chronographs and the difference amongst the 24" bolt, 24" semi auto, and the 20" bolt was 50-75 fps. This showed me that the convenience of the shorter bbl (especially if you are hunting from a blind) far outweighed the neglible loss of velocity.

I think that this is all the confidence I need to feel secure with the 20" barrel. Like you said, when you are working from the confines of the blind, any length you can take off of the rifle will be welcomed. Primarily, the gun will be used for a few duties, black bear over bait (distances under 75 yards), deer hunting from a blind (distances under 100 yards), and maybe some things I haven't thought of yet LOL. Thanks for all of your help in making my decision guys.

I have the very rifle you are looking to get you will not be disapointed these rifles will shoot as far as velocity loss i dont think and animal i have taken with mine could tell the difference.. chad

Right! A 20" or even an 18" in .308 is plenty adequate-you'd lose maybe about 100 FPS vs a 24" barrel. So what? No game would ever know the difference-I have seen this much variation from shot to shot from rounds of factory ammo from the same box!!

Excluding all semi-auto rifles, .25 - .308 calibers will lose or gain 35-40fps per inch of barrel. I have one 20in 270win and one 26" 270win and the fps change with the same loads is an average of 240fps. From 0-300yds isn't enough to really worry about but at longer ranges it sure takes alot more guess work out of your shots. I prefer the longer barrels in bench shooting and hunting. For tactical and fast I prefer the shorter barrels.

My "go to" gun is a Winchester M70 Lightweight in .308 Win.
It is very similar to the Remington M-7. It has all the punch you need, and with an 18" barrel, it does make an excellent deer blind gun, so don't sweat a few inches of barrel length!