Take a look at long guns throughout history and you’ll find that the front sight on just about every one of them is mounted in the same place – the very end of the barrel. Mounting the front sight on the end of the barrel maximizes sight radius, increasing the likelihood of an accurate shot. On the AR15 platform, many front sights are mounted at the end of a free floating rail. By definition, the rail moves independently of the barrel, meaning it is possible to have a shift in zero if the hand guard is bumped or has pressure applied to it. At long distances these shifts are magnified greatly, making it near impossible to place an accurate shot.
It’s worth mentioning that all zeroing adjustments (windage and elevation) are made on the Dynamount front sight. This allows you full use of windage on your rear sight should you need it in the field. If you want the ultimate front sight for your AR15, the Ultradyne C4 Dynamount is the sight for you.