Problem With Mounting Red Dot Scope On M&P-15

[Warren Sear]

I am trying to mount a red dot scope on a M&P-15. The scope fits onto the gun just fine, but the front sight base stands up right in front of the red dot, blocking the view of the target through the scope. What seems to be needed is some sort of riser to elevate the scope about an inch. Is this a common problem? Is there an easy solution?

The problem can be seen in the picture...

 

[Kodiakco]

You need to use a riser that will allow you to cowitness the sights and the red dot.

CoWitness Explained - by Dimitri With Primary Arms - YouTube

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[Warren Sear]

You need to use a riser that will allow you to cowitness the sights and the red dot.

CoWitness Explained - by Dimitri With Primary Arms - YouTube

Sent from my SM-G930V using Tapatalk

That explains the problem, but does not provide any insight on how to fit it. Where can these risers be purchased? Do they come in various heights? Thanks in advance.

 

[Westie1]

If you're looking to not see the front sight, not going to happen unless you remove a good chunk of the sight. All red dot mounts for the AR will have the front site visible to some degree. This is due to how the AR was designed from the start.

 

[vortex360]

That explains the problem, but does not provide any insight on how to fit it. Where can these risers be purchased? Do they come in various heights? Thanks in advance.

Google "Absolute Cowitness Riser Mount".

 

[Rastoff]

Yes, it's a common issue with the fixed front sight. Here is what you need: TRUGLO(R) | Riser Mount Picatinny 1"- 1 Piece

That's a fairly inexpensive one. They come in different lengths and heights. Measure what you need for height and we can help you find one to fit better. The one linked above will work though.

What brand/model of sight do you have?

 

[TripLeader]

You should get a lower 1/3 cowitness riser. It will give you better visibility over the front sight post. It's a higher riser than absolute cowitness.

 

[Warren Sear]

Thank you for the replies, gentlemen. That should solve the problem.

A little additional info; this is not my rifle, but belongs to a friend that I am trying to help out. The funny thing about all this, is that he is not really a "gun guy", but is so angered by the tactics of the anti-gunners and corrupt news media, that out of spite he went out and and bought a Bushmaster and S&W AR-15's and two AK74 rifles!

 

[agksimon]

This is the very reason I bought an optics ready version M&P. I don't need a co-witness, as the optic I use is a Vortex Spitfire, a prism scope, with an etched reticle and is extremely rugged to abuse.

 

[Muss Muggins]

If you're looking to not see the front sight, not going to happen unless you remove a good chunk of the sight. All red dot mounts for the AR will have the front site visible to some degree. This is due to how the AR was designed from the start.

Not exactly. Original AR's have an integral carry handle upon which the original Colt 4X20 optic fits quite nicely. Ask me how I know . . .

 

[Warren Sear]

Yes, it's a common issue with the fixed front sight. Here is what you need: TRUGLO(R) | Riser Mount Picatinny 1"- 1 Piece

That's a fairly inexpensive one. They come in different lengths and heights. Measure what you need for height and we can help you find one to fit better. The one linked above will work though.

What brand/model of sight do you have?

Thanks for the information. He has a TRUGLO (I don't see a model number on it). It looks to me like it needs 1-1/8" rise, but 1" is the closest standard, and the reviews say it will work fine. I am going to order it today.

 

[Warren Sear]

This is the very reason I bought an optics ready version M&P. I don't need a co-witness, as the optic I use is a Vortex Spitfire, a prism scope, with an etched reticle and is extremely rugged to abuse.

Can you describe what makes an "optics ready" rifle, please? I didn't know there was such a thing. My only AR's have been the old Colts with the skinny barrels.

 

[Rastoff]

Can you describe what makes an "optics ready" rifle, please? I didn't know there was such a thing. My only AR's have been the old Colts with the skinny barrels.

As the name implies, it comes from the factory ready to mount any optic. Take a look:

No sights. So, in your case, the front sight would not be in the way. It's just one way to go if you know you're going to mount an optic. If you're not sure, the standard M&P 15 Sport II is the right way to go because it comes ready to shoot out of the box. Once you decide to add an optic, the upgrade is still easy. You just need a little knowledge on how to get 'er done.

 

[Kodiakco]

M&P 15 OR (Optics Ready). Of course other manufacturers make similar rifles.

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[Rastoff]

I wish I had thought to post a pic like that.

 

[Kadonny]

@Rastoff, Yup you are not as quick on the draw as him I guess.

A little additional info; this is not my rifle, but belongs to a friend that I am trying to help out. The funny thing about all this, is that he is not really a "gun guy", but is so angered by the tactics of the anti-gunners and corrupt news media, that out of spite he went out and and bought a Bushmaster and S&W AR-15's and two AK74 rifles!

I certainly hope he will get some outside training on these rifles if he has never owned one or shot one....not being a gun guy and all. Maybe you could use a little more schooling yourself? No disrespect, but the red dot/front site post witnessing is pretty basic stuff so it might help you to learn some more about these guns too. Good luck and enjoy.

 

[Rastoff]

@Rastoff, Yup you are not as quick on the draw as him I guess.

See post #13, you know, the one that comes before #14.

 

[Warren Sear]

@Rastoff, Yup you are not as quick on the draw as him I guess.




I certainly hope he will get some outside training on these rifles if he has never owned one or shot one....not being a gun guy and all. Maybe you could use a little more schooling yourself? No disrespect, but the red dot/front site post witnessing is pretty basic stuff so it might help you to learn some more about these guns too. Good luck and enjoy.

He was in the Soviet army in his younger days before emigrating to the U.S. I bought my first AR-15 in 1981.

I will acknowledge I do not know much about the sight naming conventions of "new" AR's. That's why I asked. Most people here are friendly and courteous. It is pretty basic stuff, but it might help you to learn more about that and jumping to (incorrect) conclusions.