M&P 15

[jmuv]

I was gifted a M&P 15 with iron sights. I am thinking about putting a red dot sight and was wondering if I needed to remove the front sight. It sticks up a few inches above the barrel. Before I spend my limited funds I would want to make sure I know what I am into.

 

[The Glockodile]

You can do the "absolute" or "lower 1/3" cowitness thing with your red dot...

 

[GNP]

Try it before you take it off, mine doesn't bother me in the least, and it's an absolute co-witness. I thought I'd hate it, but I got used to it within a half hour or so. With the sights and red dot set up this way you can very easily verify that both sets of sights are zeroed to the same place, and by keeping the irons in place you have a backup in case the red dot fails.

 

[gotboostvr]

I prefer to have the front sight tower such as yours on my carbines with red dots.

It's not a problem.

 

[BreechFace]

That’s a nice carbine, if it’s the M&P 15T than it should have the 1:8 twist 5r barrel doesn’t it? Those are accurate barrels.

like others have said get yourself the red dot and research pictures of “absolute co-witness” and “lower 1/3” and see which mount you want to try. You can always change out the gas block front sight for a low pro gas block in the future.

 

[Rockrivr1]

Have that AR and my Aimpoint co-witness on the lower 1/3rd with the front post. Not a problem at all. It’s easier then replacing the post.

 

[beagler]

Keep the front sight. When you co witness the red dot you will still see the sight but it will not bother you. I was skeptical at first too. It’s nice because if the red dot goes down while you need the rifle, just flip up your rear sights and fire away.

 

[rbernie]

One nice side effect of an absolute co-witness, meaning a red dot whose dot is superimposed on the iron’s point of aim, is that you can move the optic from rifle to rifle and re-zero it easily by simply aligning it back to the iron sight’s sight picture. I am a big fan of an absolute co-witness.

 

[Walkalong]

I've never seen that point made before, something to consider.

 

[Mike .45]

It's a little hard to see when I zoom in on the picture but it looks like there is no dust cover or forward assist. If so that would be a first gen M&P Sport.

My understanding is that early models have the nicer barrel and later models got switched to a less expensive barrel. If you have a 1 in 8 twist barrel you have the upgraded one.

For irons and red dots I like to go lower 1/3rd if they are fixed and absolute co witness with flip ups.

Don't sweat it if you have the 1 in 9 twist barrel. I have one and it's accurate enough and it's been plenty reliable.

 

[OrangeCat]

Something else I've noticed with an absolute co-witness is that I, personally, can use a lower setting and it seems like the dot is a little cleaner when viewed through the peep

 

[jmuv]

It's a little hard to see when I zoom in on the picture but it looks like there is no dust cover or forward assist. If so that would be a first gen M&P Sport.

My understanding is that early models have the nicer barrel and later models got switched to a less expensive barrel. If you have a 1 in 8 twist barrel you have the upgraded one.

For irons and red dots I like to go lower 1/3rd if they are fixed and absolute co witness with flip ups.

Don't sweat it if you have the 1 in 9 twist barrel. I have one and it's accurate enough and it's been plenty reliable.

Right, no forward assist and no dust cover. It shoots good and accurate (once I adjusted the sights) but my eyes pick up red dots better these days.

 

[Mike .45]

I'd run that with a red dot with a lower 1/3rd riser or mount and keep the current irons. Here is my 12.5 SBR set up. On my other rifles I like to mount the dot further forward on the upper but the old style eotechs have a really long battery compartment.



I dont really notice the irons when I'm using the dot.

 

[jmr40]

Flip a coin. I don't think having the front sight is a problem, but if you want to remove it, I don't see a downside either. I'm not a huge dot sight fan but have 2 AR's with 1-4X scopes on them and I kept the front sights. At least for now. I don't ever envision using them, but just haven't gotten around to sawing them off.

 

[DustyGmt]

If I had to guess, I'd say with fixed FSB's and red dots, I would say that lower 1/3 co witness is strongly preferred by most over absolute. I tried absolute first, didn't hate it but also didn't especially like it and felt it was worth trying a lower 1/3 mount and like it much better, hands down.

I prefer the dot to be completely independent the front sight, and using the front sight as a quick reference or having it as a backup, not used in conjunction with the dot/sight at the same time. To me, I feel a certain degree of precision is lost when you crowd your sight picture with the front sight covering a portion of your target and on top of that you're stacking a dot on top of it, not for me. I will say that for CQB, it probably won't be much of a factor and you will still be able to just place the dot and put rounds wherever the dot is, it's really just a matter of preference and I prefer L⅓.

 

[Craig_AR]

Keep the existing sights and get a tall riser rail to mount the RDS for co-witness. I put a Bushnell TRS-25 RDS on my S&W Sport AR and the resulting options for iron or dot work great. You may have to experiment to get the correct height tall riser rail.

 

[DustyGmt]

I was gifted a M&P 15 with iron sights. I am thinking about putting a red dot sight and was wondering if I needed to remove the front sight. It sticks up a few inches above the barrel. Before I spend my limited funds I would want to make sure I know what I am into.View attachment 1042874

What, if you don't mind my asking is your budget for this red dot? If I was you and I had the money, which at this time of year is pretty tough but the way I'd look at it, even if I had to wait a bit, would be that since I am ahead on the rifle having been gifted to you and all, I might feel a lil better about spending a bit more and gravitating away from the Vortex Sparc, Romeo, etc, budget optics and go for something like an Aimpoint or Trijicon.

 

[jmuv]

What, if you don't mind my asking is your budget for this red dot? If I was you and I had the money, which at this time of year is pretty tough but the way I'd look at it, even if I had to wait a bit, would be that since I am ahead on the rifle having been gifted to you and all, I might feel a lil better about spending a bit more and gravitating away from the Vortex Sparc, Romeo, etc, budget optics and go for something like an Aimpoint or Trijicon.

I will likely go with one of the lesser expensive ones. I can go for one of the midrange SIG or Vortex. Since I am unable to work and increase my income I kinda can’t justify more on a want and not a need.

 

[crestoncowboy]

I've even put a regular zooming rifle scope on them and used them for varmint. Due to the parallax the front sight just disappears in the scope Lol.

 

[DustyGmt]

I will likely go with one of the lesser expensive ones. I can go for one of the midrange SIG or Vortex. Since I am unable to work and increase my income I kinda can’t justify more on a want and not a need.

Understood. You might also consider Primary Arms AMD or Holosun. I have an aimpoint and a couple of the primary arms micro dots. For around $180-$200 they are very good dots in my opinion. I have one that has held up very well, maybe not quite 5k rds on my M&P w/ PA micro and nothing but good results, holds zero, nice crisp dot. The only thing I might have splurged a lil on is a better $70-$80 mount and not buy the $30 primary arms mount, that's pretty chintzy feeling, but works. Just careful not to over torque

 

[DustyGmt]

I'd run that with a red dot with a lower 1/3rd riser or mount and keep the current irons. Here is my 12.5 SBR set up. On my other rifles I like to mount the dot further forward on the upper but the old style eotechs have a really long battery compartment.

View attachment 1043079

I dont really notice the irons when I'm using the dot.

Nice BCM 12.5 Mk2 upper? I sometimes wish I'd went with a 12.5?

 

[Mike .45]

Nice BCM 12.5 Mk2 upper? I sometimes wish I'd went with a 12.5?

Yup a Mk2 upper. The 12.5 is nice. It's pretty gassy with the can on though.

 

[Mike .45]

OP in that mid price range Holosun is hard to beat. Tough optic with lots of features.