www.expresssights.com/tactical_sights.html
I want to put an illuminated front sight on my wife's Lt. Wt. Carbine (A-1)
Round top, Square Top, Big Dot, or Standard?

OK others will disagree but here was my reasoning.  I wanted to have the same sight picture during the day as at night.  At night you will sight in with a green glowing dot so during the day you want a white dot.  So for that reason I chose round top.  Also you want the aiming dot to be as close to the same as possible.  The thicker the white the more the green dot and white dot will be off.  Also the sight is closer in a carbine so its more easily seen and you can make finer adjustments to shooting.  I picked small dot.  With a 20" barrel and the front sight further away I would have picked a big dot round top.  I am sure noone will agree with me and they will say big dot because its faster. (and it is somewhat)

I like the round top as well but found the big dot to be more of what I wanted.

-Kevin

Round top, big dot. The big dot is awesome. It shows up VERY quick and easy. In addition, at dusk when it is too dark to see the white outline of the standard size, but too light for the tritium to glow, that big white dot stands out like a sore thumb. They are great. Have them on my carry gun as well.

Thanks guys appreciate the input...

DevL what you said about carbine length vs 20" makes sense..

She uses an Aimpoint as her main sight so I just wanted a reliable fast CQ/B sight..I'm going to assemble another upper for her with a compact acog on the carry handle..I think for her the larger round top  will be the ticket..with the AO sight

Again thanks all...

Unless you zero the rifle using the dot itself as the aiming point folks almost universally shoot very high at night where the dot is predominant.  This means a change in sighting procedure using the dot rather than the top edge of the sight itself.

By their very construction these sights don't offer precise zeroing but do work well in low light, close range situations.

I've got one on my Dissipator upper receiver -- not sure if it's round or square off hand.  It's not a sight I use for 9"x9" steel plates at 100 meters.....

-- Chuck

Round top, small dot will have less change in point of impact between daylight and nighttime use.  It is also narrower in width and will allow for more precision in long range use.  (As will the square top, small dot variant.)  I use the small dot on my .45 and it's as fast as the big dot and much more precise. YMMV

Mine is the smaller round top, just looked at it.  The dot center is a good 1/10" below the top of the post, about the same as cranking up the rear sight on a carbine to 600 meters.  On the carbine that computes to about a 13MOA shift or call it 3" at 25 yards.

Not an issue at close range where you need to put something on the target, but not good for precision work since the bullet can be over a foot high at 100 meters.

Hopefully someone in warmer weather can see where these sights shoot in the dark at 100 meters.

-- Chuck

9divdoc,

       I had a freelance gun writter (wrote an article in the 2002 Guns Combat Annual) that was T&Eing the Ashley sights....He approached me and asked me to try a set and let him know what I though....

        I used the large dot, round sight during an OPS Tactical Carbine course last summer...I really liked this front sight for CQB work, I had been shooting the standard A2 front sight for the last 12 years, so at longer distances it took a little retraining but I can shoot just as well at longer distances with the Ashley Outdoors front sight as I could with the A2 sight...

        I tried both the large and standard square top front sights, but found that I liked the Large Round Top better than the others....The large dot is quick to acquire during close engagements, yet the round top of the sight allows more presise shots at longer distances....Just my .02