Depends on the exact sights used. The most common are a rear notch sight, and a front post. The post should be centered in the rear notch, and the top of the front sight post even with the top of the rear sight. Point of aim is usually the center of the target.
you aim down the iron sights faster.
If you are meaning ADS it means aim down sights and when you get sleight of hand pro it means you can aim down your iron sights faster than normal. Good for quickscoping.
No.
Look through your iron sights, or plastic sights, or whatever.
Check w/ Browning, but I think you are correct- BOSS will interfere with iron sights.
most of them were iron sights, very primitive v notch or battle sights
Wolfenstein 3D
No. Iron sights or peep sights (aka aperature sights) are the only type allowed for the merit badge.
In AIT you'll probably only use iron sights, which you need to get the hang of before you move to reflex sights and optics.
"Big Iron' was a term oft associated with the Colt SAA
Try e-gunparts.com
A barking iron is a tool used to remove the bark from trees, or a slang term for a pistol.