S&W M&P 15 Uppers

[K_Dubbya]

Greetings all!

I have a MP 15 that has a iron sight upper. I would like to get a flat top upper (no iron sights).

I do not have much experience with upper receivers does anyone know if it would be cost effective to purchase an aftermarket upper (if so any ideas?) or purchase a flat top upper from S & W? Or should I just build a new rifle?
Im trying to save as much money here as possible. Thanks

-Hans

 

[MyOpinion]

What are you wanting to do with the new upper?
Put a scope on for deer and varmints?
Long range games?
Maybe even a different caliber?
Uppers can be built to your exacting specification thus controlling cost.

 

[K_Dubbya]

I use it for tactical purposes, Im in the military and I shoot quite often. Sticking with .223/5.56 I will have an eotech and magnifier. I'd like to sign up for carbine courses i.e. magpul dynamics... Honestly I just need a new barrel but down the road Id like to build a 2nd AR so it would be nice to already have two uppers. I would like to stick with a S&w if possible but Im open to other companies.

 

[imac98374]

You could replace the front gas block without spending too much. If you wanted to go ultra cheap you could even grind the sight posts off of your current block, haha. The best thing to do might be to raise your eotech. With a lower 1/3 cowitness, the front sight pretty much disappears. Larue sells a riser that accomodates the sight and the magnifier, plus you get QD capability. Annnd you can still have your BUIS.

 

[K_Dubbya]

Yeah good point, Id have to look at it when I get home I dont know if I can take off the gas block/ and I dont know how to do that (Ill find out though). I could raise the eotech but in the event I wanted to resort to my iron sights wouldnt the front sight post be obscured by the optics or would the 1/3 be low enough? Currently if Im looking down the sights with the Eo-tech I can still see the front sight but I cannot se the base of the sight aperture (I can still shoot). Haha no grinding.

 

[imac98374]

I used to have an eotech 516 (so it came with 7mm of lift built-in), with the rear sight flipped down, the front sight post seemed to pretty much disappear, When I flipped up the rear, I could still get a solid sight picture. If you're interested in keeping irons as an option, I wouldn't mess with the gas block, you should be GTG as is.

Honestly, if you're running magnification behind a lower 1/3 cowitnessed eotech, I don't even think that the front sight post will be in your field of view (correct me if I'm wrong, I've never actually ran it like this.)

 

[K_Dubbya]

I have an eotech 517 (buttons on the left side) I attached an example of what I see when I look down my sights. (Which Is why Im considering just purchasing a new barrel/upper)

 

[imac98374]

Yeah, I think I got a little bit of that with the large aperture, but with the small I don't remember any? I think I tried it with the large (and the small obstruction,) and it was still good enough for soda cans at 25M, which was good enough for me.

 

[ugaarguy]

Hans,

No need to replace the whole bbl, nor the upper, Just get a new gas block - either railed so you can add a back up iron sight (BUIS) of your choice later, or with a flip up sight already built in. Then take the rear sight off, and replace with a flip up rear BUIS. If you get a new bbl. put on, the FSB / gas block will have to come off anyway to take the old bbl. off. So, unless you just want a different twist or finish (or something like that) there's no need to change the bbl.

Alternately, you could just try a riser for your EoTech for a lower 1/3 co-witness. The riser is probably the least expensive option as well.

 

[gotigers]

+1 for just replacing the gas block. Not difficult to do.