m&p 15 buis

[xtrmn8tr]

can anyone tell me if there is a BUIS called UTG...reason i'm asking is... i bought my brothers M&P 15OR and the BUIS seem of poor quality...there is a large wheel under the rear sight for elevation...about the size of a quarter($.25 cent piece)...the front sight is on the gas block (i believe it is called)...appears to be made of aluminum alloy ...i'm thinking the Troy Battle Sights would be of better quality...am i on the right track with my thinking? can i even use the Troy Battle Sights?

[JaPes]

Yes, yes, yes, and yes.

[storeyteller]

Right on! Welcome to the forum and congrats on an awesome rifle. Post pics when you can.

[cyphertext]

UTG makes many accessories that are less expensive and some are of questionable quality. I have a set of those on my .22lr, and they are ok for that role, but I will be replacing them.

If you like that style of sight, LMT makes a set that are good quality. I recently purchased the LMT rear sight from someone who took it off their stock rifle. Haven't decided which rifle is going to get it though, my Sport or my .22lr. You can also make a similar sight by cutting down a carry handle. There are many tutorials available on the web.

My Sport is currently set up with a MaTech rear folding BUIS that I bought from another user here. If you are interested in one of those, we can PM him to see if he still has any available.

The Troys are highly regarded as well, but I do not have any experience with those.

[Plazzman]

Just bought this for my Sport. ARMS40L A.R.M.S. #40L Low Profile Flip Up AR15 Rear Sight -

[Foxtrot]

Yes, you can use Troy sights. The M&P15OR is same plane sighting (in this case gas block rail at same height as receiver rail) - so you need sights that are for same plane.

Front Sight: Troy BattleSight Front M4 Folding

Rear Sight: Troy BattleSight Rear Folding

If you are thinking about Troy sights, the above are what we use. They are .50 MOA adjustment per click - and fold to 0.460.

A little pricy for some, are on par for pricing as other metal quality sights maybe +/- $20.00 average approximately depending on where you get them but worth it. You can get Troy sights with a little better pricing most times from a dealer instead of from Troy directly, for example > Primary Arms - Troy BattleSights

Just make sure you stay in the same plane for sights on the M&P15OR for what ever you end up getting. For example, the ARMS40L A.R.M.S. #40L Low Profile Flip Up AR15 Rear Sight mentioned above by Plazzman, thats not in same plane, but they do have a same plane version which is the ARMS40L-SP: A.R.M.S. #40L SP SAME PLANE LOW PROFILE FLIP UP REAR SIGHT.

For the M&P15OR and other S&W M&P15 with same plane sighting do not get rear sights that are for use with a different sight line. I'd also stay away from plastic (polymer or others) sights.

[TangoFoxtrot]

Originally Posted by JaPes

Yes, yes, yes, and yes.

Like he said ^^^^^

[ZeroTolerance6]

You can certainly spend more money on a potentially non-existing issue.
Have you fired the rifle? Is it accurate? Does it hold zero?
Or...do you not like the "look" of the current BUIS?
Is your plan to shoot with the BUIS most of the time, or are you going to invest in optics and never use them?
Just a few questions that I pondered when I replaced my A2 front post to a gas block and folding sight. I wanted to go with good sights like Troy, but decided to put more of my money into glass (which is what I use 99.9% of time when I shoot).
Welcome aboard and go shoot that thing.

[cyphertext]

Originally Posted by Foxtrot

Yes, you can use Troy sights. The M&P15OR is same plane sighting (in this case gas block rail at same height as receiver rail) - so you need sights that are for same plane.

Front Sight: Troy BattleSight Front M4 Folding

Rear Sight: Troy BattleSight Rear Folding

If you are thinking about Troy sights, the above are what we use. They are .50 MOA adjustment per click - and fold to 0.460.

A little pricy for some, are on par for pricing as other metal quality sights maybe +/- $20.00 average approximately depending on where you get them but worth it. You can get Troy sights with a little better pricing most times from a dealer instead of from Troy directly, for example > Primary Arms - Troy BattleSights

Just make sure you stay in the same plane for sights on the M&P15OR for what ever you end up getting. For example, the ARMS40L A.R.M.S. #40L Low Profile Flip Up AR15 Rear Sight mentioned above by Plazzman, thats not in same plane, but they do have a same plane version which is the ARMS40L-SP: A.R.M.S. #40L SP SAME PLANE LOW PROFILE FLIP UP REAR SIGHT.

For the M&P15OR and other S&W M&P15 with same plane sighting do not get rear sights that are for use with a front A2 type sight height which means you can't use something like the MaTech rear folding or other sights that are for use with a front A2 type sight height. I'd also stay away from plastic (polymer or others) sights.

Foxtrot, your definition of "same plane" differs from what I was taught. Same plane refers to having a dual apertures on the rear sight, where the center of each aperture is at the same height over the barrel. The two different apertures allowed for shooting at different ranges without the "need" to change your zero. The carry handle type sights are not same plane, as the center of each aperture is at a different height over the barrel. This type of site typically has elevation adjustment on the rear sight as well.

I was under the impression that on the gas block sights, they have two sizes...one for the "standard" gas block rail which is lower than that of the receiver rail, and one for the gas block rail that is of the same height as the receiver rail, which you are referring to as same plane. You choose the sight that corresponds to your gas block height and this will set your front sight pin to the same (or close enough) height as a standard F marked FSB. Then you would be able to use BUIS like MaTech, Magpul, or other standard height BUIS.

[Foxtrot]

Originally Posted by cyphertext

Foxtrot, your definition of "same plane" differs from what I was taught. Same plane refers to having a dual apertures on the rear sight, where the center of each aperture is at the same height over the barrel. The two different apertures allowed for shooting at different ranges without the "need" to change your zero. The carry handle type sights are not same plane, as the center of each aperture is at a different height over the barrel. This type of site typically has elevation adjustment on the rear sight as well.

We are talking about the same thing. I just mentioned the gas block and rail height because its eaiser to visualize and match to whats available for same plane as some manufacturers will say something like "will not work on gas block rails lower than receiver" or similar but the sight is still same plane. So its just a reminder that everything is the same height.

Let me see if i can say this without screwing it up completly:

Same plane is in reference to the rear sight apertures using the same non-changing sight line shared between the two apertures and the center of the apertures remain the exact same constant height above the bore line. The two apertures do not have an intersecting sight line axis at zero but rather use the same sight line which is the same at zero, the sight line does not converge or diverge with distance but remains the same.

It looks like this from the line of sight perspective:



Elevation at the rear sight is really bullet drop compensation, point of aim for point of impact elevation is at the front sight.

Originally Posted by cyphertext

I was under the impression that on the gas block sights, they have two sizes...one for the "standard" gas block rail which is lower than that of the receiver rail, and one for the gas block rail that is of the same height as the receiver rail, which you are referring to as same plane. You choose the sight that corresponds to your gas block height and this will set your front sight pin to the same (or close enough) height as a standard F marked FSB. Then you would be able to use BUIS like MaTech, Magpul, or other standard height BUIS.

They do have two heights for gas blocks, and like you said one for lower than receiver rail and one for equal to receiver rail. However, in relation to same sight plane the measurement of the sight post height begins at the rail (sight base at rail interface)

If you use a proper front sight the Matech will work fine, not saying it won't. I was trying to use the A2 front sight as reference so it could be visualized as an example reference, but said it wrong I guess. I changed it to be less confusing and more generic and you missed the later edit.

[cyphertext]

Originally Posted by Foxtrot

Let me see if i can say this without screwing it up completly:

I had to go edit mine, because I screwed it up the first time around...