I'm going to buy a new rifle soon, a heavy barrelled .308 tactical rifle, to get into more serious target shooting at all ranges, but I also want to get some instruction and try my hand at 600 and 1,000 yard shooting. The rifle has a 1:10 twist, but is available with a 24" or 26" barrel. Which would be better? Most data I've seen for the .308 is written for a 24" barrel, so I figured having a 24" barrel might make it a little easier to figure out the numbers. But more importantly, I'm wondering about the 26" barrel, does that extra 2" provide enough extra velocity to make a noticeable difference for the better?