The Skinner barrel peep sight is cool, but I think Skinner's a little off base with the aperture sizes. The largest available one was pretty small for the front sight but might have target applications. The peep with no aperture (just bare threads) was about right - still small enough to shoot more or less the capability of the rifle IMO but faster for dangerous stuff.
The smaller ones strike me as completely useless, or maybe for exceedingly long barrels. But my 1886 has a 26" so there's a limit to how much longer a barrel you'll see. I think they just didn't field test it or else someone at Skinner has much better eyes than me.
