If I mainly shoot out to 300 yards and occasionaly shoot out to 1000(may do it more if it gets addcitive), which barrel length would be the best? There are two rifles I have in mind, they both have 1/10 twist but one is 20" the other is 24". The one that is 24" has a brake and a detachable magazine. The magazine part I like but is 24" too much? This will be my second rifle setup and I have limited experience.