AR-15 front sight question

[socalbeachbum]

In shopping for AR-15's I was told to not worry about the front sight getting in the way of the sight picture through a scope, that even though it is directly in the center of the sight picture, anything so close to the scope isn't visible. The sales guy showed me and I was surprised.

My question is this, is this still the case with a non-magnified red dot sight? Are there any negatives to having a permanently affixed A2 type front sight on a 16" carbine model?

 

[1911 guy]

Folks, including me, do it all the time. Military, also. When using a red dot, there are two common methods used and which one is a matter of personal preference.

First, and most popular because all the cool kids are doing it, is lower third co-witness. This means that the red dot will appear above the front sight post of your rifle. The iron sights will appear in the lower third (approximately) of the red dot tube or viewing window.

The other method, my preference, is absolute co-witness. The red dot sight is mounted slightly lower, which places the dot on the top of your front sight post and your iron sights in the center of the tube or viewing window of the red dot sight.

One method is not intrinsically better or worse than another. Some sights come with multiple mounts/risers and let you make up your mind after purchase, others require you to order the specific mount for your desired application. Not really a measure of dot sight quality, just sales.

 

[Tirod]

Co witness allows you to still be able to shoot by looking thru the window of the red dot even tho it failed. In the early days it was common enough as battery life was short and the electronics in some models not shock resistant. By "shock resistant," hold the weapon over your head and toss it forward onto concrete. That simulates what happens if you drop it climbing down out of the typical high bed trucks used for transport in the service. And it happens all the time.

Military grade red dots are not required to have shatterproof glass lenses. Abuse in the field can fill a light equipment repair company storage conex over months in country. Nobody is saying but I speculate the service life of a red dot in the field is less than the tour of duty for the solder carrying it if he's Infantry or patrols extensively. We will likely not get that info as the maker's are extremely close about the performance of their products and don't want to share anything that would be considered negative.

Take a tour overseas and you quickly learn anything that can break will when your buddies throw your pack or duffels as hard as they can onto concrete aprons from the back of a truck, then onto another truck, then back down onto concrete, then onto a conveyor, then into the cargo hold of an aircraft, and as it fills up they stand on them, too.

And we treat our weapons with nearly the same consideration. Fly and it goes on the floor under your feet for 24 hours. All that means you start out on patrol with a broken optic with no option other than to use it co witness thru what is left of the sight picture. This is why Kyle Lamb suggested truck guns shouldn't use them - they get beat too much to survive as their ruggedness isn't that extreme. Again, they don't use shatterproof lenses.

Annoying considering the price.

 

[socalbeachbum]

so I think this means I should buy the AR-15 with the front sight. and avoid the models with no sights.

 

[chicharrones]

If you want to see what the view through optics looks like on a fixed front sight AR, here are some photos of optics I have tried and owned.

Lower 1/3 co-witness through EOTech 517.

Lower co-witness in a tube type red dot (DIO RV2).

Through a 1-4x scope set at 1x (true 1.4x). Note that the camera makes the front sight look much clearer than it does to the eye. You will not be able to use that front sight through the scope due to the close focus range being well past the rifle.

 

[AK103K]

Its really not a negative, but its an annoyance to me. It just clutters up the FOV, and with the other options available, its not necessary. I much prefer a clean FOV and get that with the fold down BUIS.

If its what youve got and it REALLY bugs you, with sights like the Aimpoints, you can just close the front cover and use them like the old OEG's. This also works well if youre moving into/out of areas of different light levels. You set the dot once and you dont have to fiddle.

 

[socalbeachbum]

so it may be simpler to use fold down front sight.

 

[chicharrones]

so it may be simpler to use fold down front sight.

For an AR that you will keep for a long time and may change out the optics in that time, I'd definitely lean towards fold down front and rear sights.

 

[AK103K]

Having the full flat top gives you a lot more options. You can always get a "fixed" front sight that goes right on the front mount, if thats what you like. Down the road, if you want something different, its easily gone.

My one Armalite is a double flat top and was set with standard AR carry handle sights. Looked very much like an old school AR.




Looked like this soon after....

 

[1911 guy]

Folding front sights are also an entirely viable option. All three variations, lower third o-witness, absolute co-witness and folding front sight (with either witness option when unfolded) are workable and somebody somewhere, or a lot of somebodies, uses each option for whatever reason.

I've also got a rifle that uses fold down sights. Suits me well as the free float tube extends past where the front sight block would be. All personal preference or depends on how the rifle is set up.

 

[DMK]

I've never been a fan of fold down front sights. It's an added expense, added weight and one more thing to fiddle with with no real benefit.

With higher than 3x magnification, the front sight will be out of focus and you won't see it. With 1x magnification, you don't need to care. You should be shooting with both eyes open and your focus should be on the target. That red dot will hover over your target and you can ignore everything else.

If you see the front sight while shooting with a red dot, you aren't doing it right. There are better places to spend your time and money.