For all you peep sight shooters I have a question for you. How difficulty is it (assuming an accurate AR platform) to shoot honest 1" groups at 100 yards with standard milspec peep sights commonly seen on the M4(not talking about match grade sight)?
With mil-spec, it's a challenge. Even though your eye naturally aligns peep sights, there is so much room in the rear sight of the standard military sight (being designed for battle and speed, not precision) that it's a touch proposition. However, reducing the rear opening slightly quickly increases precision. I've shot 1 1/2 MOA with match sights in a blackpowder rifle at ranges up to 500 yards.
