Review: Magpul MBUS Pro Offset Sights

[zimagold]

Summary:

1. After some initial issues that are detailed below, sights work well and I would recommend for anyone looking for a pair of offset irons. Good performance vs. Cost.

2. I found 1 issue with the design, they would not properly mount in the rear section of a VLTOR MUR style upper. This may also be a problem with some billet uppers.

3. Personal preference, I find the offset irons to be slower than a red dot in a 45 degree offset, but faster than a red dot mounted over the top of an optic. YMMV.


---------------------------------------------------


Review: Magpul MBUS Pro Offset Sights

These offset sights came out in November of 2014 and I haven’t found a whole lot of reviews. Admittedly offset sights are a bit of a niche product. I have been debating about trying a cheap pair ($20 Amazon) to play with the concept of offset sights rather than buying the ~$280 KAC version when these launched and I figured I would take the plunge.

Source: Botach.com
Price: $143 Shipped for Pair

Installation:

Front sight had no issues clamping in place. One problem I encountered was clearance on the rear sight. I mounted the sights to a Noveske brand VLTOR MUR Upper. Due to the style of forward assist and deflector block, there is only one slot on the top rail where the rear sight could be mounted. Even in that one slot, the rear sight seems to touch slightly on the forward assist area (Circled in Red on attached picture). Hopefully it sights in OK. If I decide to keep the set, I may remove some material on the rear sight.

Basic Function:

The sights snap nicely into and out of upright position. They do not lock in the upright position, but have firm retention. Click adjustments are stiff, but each click is easy to distinguish. I have not had a set of Magpul Pro sights before and I did not realize there are two apertures on the rear sight. I was initially concerned sighting down the rifle as the rear sight appeared to be too small for fast target acquisition. I then folded down the aperture and realized I had been in the small position. I have pictures showing both apertures and the image taken a little further back is in the large position. Sighting in the garage the concept felt good so far.

I will follow up with a range report.

Let me know if you have any comments or questions.

[zimagold]

Overall picture of install.

54965

[zimagold]

Range Trip 1

Unfortunately, sight in with the offset sights did not go as well as hoped. I started at 25yrds, the first group was low and way to the left. I maxed out the windage adjustment at 48 clicks right and still was shooting left.

At this point, I decided to move out to 50 yards and set the elevation. I also switched to my left hand (I am naturally left eye dominant) just in case it was shooter error due to an eyesight issue. Things improved a little, but it was still off to the left with the windage maxed out to the right. Elevation set fine. Target from sight in attached.

I have a feeling this problem is being caused by the minor binding issue I pointed out above on the rear sight. I also have never had iron sights on this particular upper and it could be a bent hand guard. I will be moving the sights to another known good upper.

Possible Issues:
A. Rear sight interference with upper is preventing sight-in.
B. Upper hand guard is not square to action.
C. Either front or rear sight is out of spec from factory.

I suspect its A or B.

Positive Notes:

1. Should hold zero well. After 48 clicks off adjustment, I am not worried about the sights being bumped out of zero. My weak office worker hands were sore after that much adjust of the sights, and I was using both hands.

2. Offset concept worked fairly well in limited test. With a Magpul UBR stock I was able to maintain a good cheek weld with the rifle rotated. Also, the smaller 2.5-10x32 scope did not block as much peripheral vision as expected. I had assumed when the rifle was rotated and the scope was in front of your left eye (Shooting Right Handed) that you would loose most of your vision. It wasn't that bad, definitely noticeable, but still a workable configuration for punching paper.

3. You can still shoot left handed with the offset sights. It was quite awkward and not comfortable, but workable. It was also somewhat disconcerting at first, with the light off in my stall at the indoor range my right eye was getting blinded by the flash off the muzzle brake.

Pictures of target and final position of sights attached.

Will post when I try with a different upper.

[zimagold]

Range Trip 2

I was able to zero the sights on another upper (20"), but they ended up 38 clicks right to zero. Looks to be a combination of A and C from post 2; Interference with the VLTOR MUR upper and the sights appear to be off as well.

I ended up moving the sights back to the original gun and mounting the rear site just in front of the ejection port. This reduces the sight radius from 18 inches to 12 inches. They can only be used with the largest aperture in this placement and feel like irons on a shotgun slug barrel. I wanted a sight to be used in parallel with my 2.5-10x scope for shots inside 50 yards. They work fine in this position and required a similar 38 clicks right to zero same as I found with the 20" upper.

Going to run these in this short configuration for awhile, then decide whether to send them back to Magpul to check alignment.

[Irving]

First time I've seen this post, and I have to say I'm very intrigued and find those sights to be super cool.

[zimagold]

Its a neat concept for an alternative to a red dot in parallel with scope.

Speed wise, my personal preference
1. Red Dot
2. Daylight Bright 1x Scope
3. BAC or Non-Illuminated 1x Scope
4. 45' Offset Red Dot
-> 5. 45' Offset Irons (Thinking they fall here based on experience with others and short usage.)
6. Red Dot over Scope (I hate breaking my cheek weld.)

Just a little disappointed I may have gotten a bad set first go around.

[Musashi]

Good to hear how this is going
I have a 4-16 PST coming for my rifle and was thinking about offset sights but may go with the offset red dot instead, maybe try one of those Vortex Venoms

[zimagold]

I was trying for something that was less expensive than a mid range red dot and mount. Its also nice to be able to fold them down out of the way when not in use.

For speed, I still think a 45 degree offset red dot is better.



Edit: Clarify.

[Guylee]

How far left is it shooting? Seems like it would make sense since the gun is canted left. I might be overthinking this, but it seems like zeroing sights that are offset 45 degrees would be difficult because they aren't directly over the bore. Not only do you have to deal with the elevation change, but the windage as well?

GEDIT: I guess it doesn't really matter much since you probably aren't using the sights much past 25 meters anyway. Or maybe you are. I don't know.

[zimagold]

At 25 yards they started off being 5 inches left. Elevation set just fine.

The design has them setting low and to the right of the upper so when the gun is rotated 45' for shooting, the sight posts are directly over the bore. This allows elevation and windage to set separately.

I also tried a second gun, BCM 20". Maybe both guns are canted, but I would be surprised with a Noveske and BCM.

[Guylee]

But if your gun is zeroed to your optic, your groups will be to the left at 25 yards because it will be POA/POI for the optic. Bullets will travel in whatever direction the gun is canted. They may be positioned over the bore, but since the bore isn't level, the bullet travels to the left.

[zimagold]

But if your gun is zeroed to your optic, your groups will be to the left at 25 yards because it will be POA/POI for the optic. Bullets will travel in whatever direction the gun is canted. They may be positioned over the bore, but since the bore isn't level, the bullet travels to the left.

I agree that when canting an optic that was zeroed in the vertical I would expect an impact shift both ahead of the first zero point (impact opposite cant) and down range of zero (impact direction of cant).

My thought was, these irons should establish a separate plane perpendicular to the bore and sight in like any other sight as long as the upper/handguard they are mounted on is parallel to the barrel and the sight plane is vertical. The only difference should be ergonomics of holding the rifle.

It wouldn't surprise me to find the barrel is a little off from being absolutely parallel with the upper and handguard, but I would have expected the error to be different between two rifles. It was the same in both cases.


Looks like I missed the Botach return period by 1 day. At this point, I think I am going to machine a shim for the rear sight and see if I can fix both problems: eliminate interference with VLTOR MUR upper and get the sight back in normal windage adjustment range.

[Guylee]

[QUOTE=zimagold;1828811

My thought was, these irons should establish a separate plane perpendicular to the bore and sight in like any other sight as long as the upper/handguard they are mounted on is parallel to the barrel and the sight plane is vertical. The only difference should be ergonomics of holding the rifle.

[/QUOTE]

You're right. I wasn't really thinking about that...

[zimagold]

I was planning on making a shim, but decided to use these offset sights on a different rifle and requested an exchange.

Went to the range tonight with the new set of sights. All is well. Sight in had no issues.

Targets at 50 yrds attached. Initial sightin, let the rifle cool, then shot a 5 shot group.

55925 55927

[zimagold]

Added summary to first post.