[downtown]

I'm looking at getting a rear iron sight for my flat top AR15 that has a standard milspec A2 front sight. I've been looking at the ARMS 40L and the 40L-SP. Also the LaRue LT103. I'm having trouble understanding the "same plane" feature on some of the sight apertures. Sorry if this is a stupid question but I'm lost. Can someone fill me in. Thanks

 

[Inebriated]

http://www.ar15.com/forums/t_3_18/497571_.html

Quick of it is the larger A2 aperture creates a higher POI than the smaller one... A same plane will not have that elevation change.

I have the DD and LaRue rear sights with the A2 aperture. For both, I just use the large aperture and ignore the smaller one.

 

[samuse]

The best rear iron I have ever used is the Larue with an XS same plane aperture. A close second would be the Daniel Defense A1.5.
I have never been able to hit much of anything with the big aperture at anything more than about 30 yards. It is easier to use at night with a light.

Are you sure you have an A2 front? It is a little shorter than an A4/M4 front. The correct front will have an F (flat top) on it somewhere. If you do indeed have an A2 front, you may need a taller post. Fulton Armory has 'em, as well as Bushmaster.

 

[downtown]

Are you sure you have an A2 front? It is a little shorter than an A4/M4 front. The correct front will have an F (flat top) on it somewhere. If you do indeed have an A2 front, you may need a taller post. Fulton Armory has 'em, as well as Bushmaster.

I checked to make sure and yes it has an F on it. So If I get the LaRue, then I don't need a taller post?

 

[jrs93accord]

Just an FYI, Midwest Industries also offers a Same Plane Low Profile rear sight.

http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=173

 

[downtown]

Just an FYI, Midwest Industries also offers a Same Plane Low Profile rear sight.

http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=173

Thanks, that sight looks tough. I'm still not sure if I need a same plane or not. Don't mean to be stupid, but I'm kinda having trouble understanding it.

 

[downtown]

The best rear iron I have ever used is the Larue with an XS same plane aperture.

I'm a big fan of XS, I have the Big Dots on all my carry handguns. Why did you choose the XS Same Plane aperture over the regular Aperture. Just trying to get an idea on what I need. Thanks

 

[jrs93accord]

Thanks, that sight looks tough. I'm still not sure if I need a same plane or not. Don't mean to be stupid, but I'm kinda having trouble understanding it.

I have a MI SPLP on one of my builds, but that is only because I needed it to fit under the 1-4x24 optic. On every other AR I have (and there are many), I use a standard flip-up rear sight (MAGPUL MBUS, MaTech, KAC, Troy/LaRue, A.R.M.S., and MI). There is no real need to use a SP rear sight, especially if you plan on using a red-dot optic at some point.

Personally, I really like the simplicity of the MAGPUL MBUS rear sight. You have one aperture and it works well with "F" marked FSBs. If you go with an A2 type rear sight, Here is some info for you.

a. The rear sight has an elevation knob with range indicators from 300 to 800 meters and two apertures for range. One aperture is marked 0-2 for short range from 0-200 meters and an unmarked aperture for normal range from 300 to 800 meters.

(1) The 0-2 (large) aperture is used for short range (Figure 107). This aperture is used only when the rear sight is all the way down. The 8/3 (300-meter) mark on the elevation knob is aligned with the index mark on the left side of the receiver.

(2) The unmarked (small) aperture (Figure 108) is used for normal range. This aperture is used for most firing situations. It is used in conjunction with the elevation knob for 300- to 800-meter targets.

b. The rear sight also consists of a windage knob on the rear side of the sight (Figure 109).

(1) Each click of the windage knob will move the strike on the round from 1/8 inch (.3 centimeters) at 25 meters to 4 inches (10 centimeters) at 800 meters.

(2) A windage scale is on the rear of the sight and the windage knob pointer is on the windage knob.

 

[downtown]

So far narrowed my choices down to LaRue LT103 or Daniel Defense A1.5. Opinions?

 

[Inebriated]

I have both, slightly prefer the DD just for the weight savings and how trim it is.

 

[Reb 56]

I have both, slightly prefer the DD just for the weight savings and how trim it is.

I have an LMT A2 for the rear sight would the fixed DD sight work with it in regard to height ? I have decided to stick with irons for a while.

 

[Inebriated]

I have an LMT A2 for the rear sight would the fixed DD sight work with it in regard to height ? I have decided to stick with irons for a while.

It should work fine.

 

[MrMurphy]

If you have no plans to remove it, the DD is fine.

I use an LT103.

 

[samuse]

I'm a big fan of XS, I have the Big Dots on all my carry handguns. Why did you choose the XS Same Plane aperture over the regular Aperture. Just trying to get an idea on what I need. Thanks

I like the SPA because I really only use my irons out to 100 yards or so.

I use the big hole for very close, low light shooting (inside or around the house with a white light). The small hole I use for everything else.

It's nice having the same POI between the two apertures. With an A2 sight, you can set the sight up to where you can zero with the small hole, and flip to the big hole and come up 4 clicks to have the same POI. But that's just a way to do what the SPA does without adjusting anything.

Unless you're on a USMC KD range, the A2 sight just doesn't make any sense.

 

[Big Bird]

I prefer the Larue over the DD and do own both. No need to spend the extra $25 for the Larue QD lever. Just buy the one that bolts on. You won't need to take it off quick for anything. And buy the same plane.

The standard A2 sight has two apertures but they are NOT the same elevation. Not because one is bigger but because one is offset for more elevation for a battlesight zero and they smaller one is set up for more precise zero. The same plane sights have two different apertures but they are exactly the same elevation and hence your zero does not change regardless of which size aperture you use and it will with the different apertures on the A2 sight.

 

[11B101ABN]

Get the DD and dont look back.

 

[CBennett]

I went with the Troy battle Sight it was on sale . and Reviews pretty much right with the rest of the ones listed.