I have a skinner peep on my cz 527. I once shot an moa group with S&B fmj. Not an everyday thing for my ability, but not far from common. With barrel mounted sights? No way
Have used skinner sights on a lot of guns. Handi rifles, Tikka, Henry, ruger american etc. They are good but the older ones were prone to rusting. Might be better now
I have a SAKO branded peep on my Aiii. It's a cool idea with the multiple ranges but both are within the mpbr of most rifles.
With the aperture threaded in it is a small window.
Maybe a holdover from the Era when scopes were not used by many. It seems like it does away with the fast target acquisition aspect of peep sights though