I find myself wondering about the difference/advantages of rear sights that are either square bottom or U-bottomed. Just off the top of my head it would seem inconsequential ... light on either side of the front post would not be affected by the "bottom" of the notch ... as would aligning the top of the sights (front and rear).

I suspect I'm missing something ... all education appreciated.

U or square doesn't matter as much as the width of the rear and front sights tailored to your preferences.

I personally like a deep notch (U or Squared) that allows me more margin of error to float my front sight in vertical and horizontal. I don't like tight light spaces or low mounted sights. Everyone is different and unfortunately we waste a lot of money and time looking for the right combo.

The point of U notches is because the eye is drawn to sharp angles more clearly than curved edges. Having the bottom of a U notch rounded allows your eyes to focus more on the top of the front and rear sight.

My preference is the Warren style rear sight, where it is a square notch, but with rounded corners.

Thank you both for the info.

For me it’s about aligning circles on circles.

Long ago when I shot in small bore competitions, it was all about aligning circles: The rear sight aperture was a circle, the front sight aperture was a circle, and the target was a circle. When all three circles were aligned, the sight picture was perfect, and that was much easier than when there were square corners and flat spots involved such as when using a blade-type front sight. The reason why is because it’s very easy to detect by eye when one circle is perfectly centered over a larger circle, and is much easier than seeing if the top of a post is centered on a circle. It’s possible to position the post on the center of a circle, but it takes more concentration and effort; aligning two circles is more automatic.

I don’t shoot small bore competition any more, but I use the same circle on a circle principle when striving for maximum accuracy with optical sights that have a circle in the center of the reticle (or just a red dot). I make my targets with a central ring that the reticle circle will just appear to fit into when aiming; that helps ensure the most accurate and consistent sight picture.

So, what does that have to do with the original question? I discovered U-shaped rear handgun sights not too long ago, and when I tried a set, I found that the large colored front sight dot aligned into the rear notch in the same circle-on-a-circle way. The notch is of course just a semicircle that’s open at the top, but for precision shooting, the front sight circle (dot) and the rear sight U made it easier to achieve the same consistent sight alignment.

I obviously don’t worry about precise sight alignment for some shooting, such as trying to hit an 10×15 inch target at high speed from 7 yards, but it’s imperative if it’s a slow fire 4×6" target at 15 yards. Good sights are only part of what’s necessary for accurate shooting, but a very important part, and the U-shaped rear notch with large front sight dot are good for me.

I'm equally incompetent with both, but I always preferred Sig's square dot-the-eye approach.

quote:

Originally posted by sigfreund:
and the U-shaped rear notch with large front sight dot are good for me.

That's my preference as well.

I like the Ameriglo UC sights. The blank U notch rear combined with the relatively large hi-viz front sight that fills most of the U notch is a combination that works well for me.

Similar to the Trijicon HDs, just with a blank rear. And the UCs aren't overly tall like the HD sights.

The only downside is that the UCs are currently only available for Glocks.



(Comes with your choice of yellow or orange front sight.)

quote:

Originally posted by Nismo:
The point of U notches is because the eye is drawn to sharp angles more clearly than curved edges.

I'm not saying you're wrong but is this really the case? How could this have been proven?

Guy's there quite a bit of marketing hype into this U notch stuff. The illusion that your eye is drawn to the front sight easier is the fact that the rear sights lack rings on the rear tritium vials or they are just blacked out. Black out your square notch sights if you have a 3-dot set up and bingo "The front sight really pops".

All we need is an acceptable sight picture, with excellent trigger control we will have an accurate hit. It's really the combo of front blade thickness and rear sight width according to our eye health, which will change person to person.

The bottom edges in the notch mean nothing if you're focusing on the front sight properly during firing.

I think the greatest point to this hype is those with Wilson Combat 92 rear sights (Yes, I do like these sights - but for the 92 we don't have many options). Take a look at the U notch and see how the front part of the slide turns it into a square notch if you really look at it. You'd probably never notice this because, it's not proper to concern your self with the bottom of the rear notch during firing.

Both sigfreund, and piedrarc make excellent points.

Here's my take.

Personal preference, proper training, are both factors, but now that I'm 48, age, specifically the age of my eyes is now a factor for me, and has changed my sight picture.

I can no longer focus on my front sight the way I could just 5 years ago.

I have Ameriglo sights on my Shield 9, large pro dot on the front, u notch with black rings on the rear.

When I put them on 4 years ago, they were perfect, and just as sigfreund described, I could put the large front dot right into the half circle rear. Now in bright light, I can still pick up the front sight pretty well, but indoors, or in dusk or dawn, the sight picture is fuzzy at best.

I just changed the rear sight on my P226 to an Ameriglo rear square notch .280" wide as opposed to .250" wide, paired with basically the same pro dot front sight.

In low light this set up is much better (for me) than the u notch, in my opinion for two reasons.

The wider notch gives me more light on either side of the front sight, and the square notch gives me more light vertically (to piedrarc's point).