"Almost" without exception your going to have a more accurate load with the bullet seated as close to the rifling as possible. The problem is the magazine. You can only load to the length of your mag IF you are going to use it. Often High Power, and others, will load heavy, long bullets seated near or into the lead. These loads far exceed the length of the mag and must be hand fed. Yes! You have discovered a very important "secret" to accuracy, whether in an AR or a bolt, single shot.