moigy wrote:1. Why pistols have usually a rectangular front blade to target a circle seems strange. Since my first Wnchester 52C with a small aperture rear sight (Lyman), I coupled aRedfield aperture sight up fromt. I bought a connecting tube (no glass) which eliminated extraneous light. The result was almost like a red dot. The front sight circle permitted just a sliver of light between that front sight and the target. When the sliver was uniform all around, I was in the X zone of the 10. It seems to me the something of that sort mightbe preferable for pistols as well. What say you all?
I say you're exactly right. However, tradition gets in the way.
Shooting under International Handgun Metallic Silhouette Association sanction has always allowed what they now call "peep-on-peep" sights, what I grew up calling "aperture" sights and what European silhouette shooters refer to as "diopter" sights. I've been using such sights on my Unlimited-class competition pistol since the 1970s. Over the years they have become quite popular in the various "stand up and hold the pistol out in front of you" classes, too.
In fact, I have on the desk in front of me as I write this a .45 auto with a frame-mounted Weaver rail to which I've attached two XS Sights "Low Weaver Backup" sights, one at each end. In use, I put the rear circle around the front circle around the target and I endeavour to make the hammer fall when it appears I'm close to a concentric arrangement. On a well-lit range and shooting at a round bull, it's the easiest-to-sight iron-sighted .45 auto I've ever owned.
As for your specific description of a sighting arrangement with a tube from front to back, "tube sights" are a known concept, too. I remember the NRA national meeting in San Antonio, Texas, back in the mid- to late-1970s. One of the exhibitors was a Japanese company making a one-piece tube sight for use in silhouette shooting. It never made it to market (and would have failed, anyway, since it didn't comport with the rules at the time). Other tube sights, however, have done quite well. Kings Gun Works in Texas built a large number of pistol tube sights over the years. I have one (currently disassembled) that my sister used for years in competition. Ultimately, it was a bit crude, bulky, and fragile so they are rarely seen these days. Back in the day, though, when they were set up correctly and mechanically sound, those were easy sights to shoot. U.S. Optics has also made such a thing to a much higher mechanical quality standard. Unfortunately, theirs was (like pretty much all their products) far too heavy and so shockingly expensive that it never made inroads into any competitive venue of which I'm aware.
On a related note, some manufacturers of sights for action-type pistol shooting games have attempted to market "ghost ring" rear sights for use with front posts. While the sights are great compromises, providing improved accuracy with only a small penalty in speed, they've not taken the world by storm. In the fast-moving sports to which they were marketed, any accuracy gains were of little benefit and giving up even a tiny bit of speed to get those gains was a fine way to lose. Since those games also frequently involve shooting to the middle of a large, blank target instead of at a well-defined bull, the sights are frequently a total mismatch to the job. Without something to aim at, apertures are a bad idea. In those venues, then, using some sort of circular rear sight is viewed as a quaint, ultimately unsuccessful experiment.
What ultimately puts the nails in the coffin for this concept, though, is that putting circles on top of pistols for sighting equipment is just too non-traditional to be considered acceptable by some people. The ISSF specifically forbids it, even though it looks like it would be a natural for the Mens 50M Pistol event. The IMSSU (which sanctions silhouette shooting in many places outside the USA) has banned their use in an increasing number of classes over the years. Basically, there's a strong prejudice against this sort of sighting arrangement by people who value tradition over hitting the target. These are the same sorts of folks who banned low bore lines in rapid-fire pistols the first time someone started making such a thing. For some folks, if the bore isn't above the hand, if the sights aren't a notch and a post, if it just doesn't *look* like the pistols our great-grandfathers used, it should be banned. Right now, those people write the rules for the big sanctioning bodies. The progressive sanctioning bodies that would be OK with the concept tend to just skip right over it and allow red dots and scopes, rendering apertures obsolete. Pistol silhouette shooting in the USA seems to be the only place where circumstances have come together to allow and encourage their use.
Without more and broader competitive venues to work out the kinks, aperture sights on pistols will remain a mostly-unexplored niche.