You don't understand the capabilities of rifles. A mile is not that far when you are shooting.
Long range precision shooting covered in detail.
85 videos that will guide you through each step in learning how to hit long range targets. Introduce your rifle to the world of long range targets.
a mile is 1760 yards. very few can make such a shot reliably and repeatedly
there’s no reason not to schedule 10+ troops to monitor/guard each mile in 3 shifts (3-4 active per shift), overseen by a command structure that allows for backup to be deployed where needed.