The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: Semi-automatics

Reply
 
Thread Tools
Old November 14, 2012, 02:06 PM   #1
Sweet Shooter
Senior Member
 
Join Date: June 17, 2011
Posts: 472
MBUS

Is the polymer rear MBUS worth considering as a main backup sight over an A2 handle? Is this rear sight tight and will it hold zero... I mean really hold zero like no movement shows up at 100 yards?

I'm in a predicament where having a slim BUIS under my ocular is pointless because the Nikon 223 cantilever scope mount will not tip off... only slide off.

-SS-
Sweet Shooter is offline  
Old November 14, 2012, 02:20 PM   #2
Crow Hunter
Senior Member
 
Join Date: January 27, 2012
Posts: 1,078
As a backup sight, they are fine. They are actually proved to be tougher than Troy and some other more expensive steel BUIS in some drop/impact testing that I saw.

That being said, I wouldn't want one as a primary sight. The aperture doesn't work for me well and they do flex a little bit.

Troy BUIS are the lowest that I have used, they will normally fit under pretty much any optic that is mounted to the correct height.

Of course, unless you have Quick Disconnect scope base, it is kind of pointless to use BUIS. If you are going to have to use tools to get the optic off, you will have time to put the carry handle back on.

What type of base do you have that requires you to slide it off the back? Are you sure you can't just turn the screws a little farther and take it straight off?
__________________
I am no longer participating in gun forums.

Good luck.
Crow Hunter is offline  
Old November 14, 2012, 04:45 PM   #3
plouffedaddy
Senior Member
 
Join Date: May 13, 2011
Location: Carolina
Posts: 3,189
Quote:
I mean really hold zero like no movement shows up at 100 yards?
All day long.

I have MBUSs on several of my ARs, many without optics and I've never had an issue with the zero on them.
__________________
Mrgunsngear's Youtube Channel
Certified Glock Armorer
plouffedaddy is offline  
Old November 14, 2012, 05:04 PM   #4
Sweet Shooter
Senior Member
 
Join Date: June 17, 2011
Posts: 472
The scope base is the M223 it is a one piece slide on base specific for flat tops. It actually means it also comes right back to zero when removed and replaced, but with the downside that it doesn't tip off. I guess it's for a varminter style AR.
-SS-
Sweet Shooter is offline  
Old November 14, 2012, 05:08 PM   #5
Crow Hunter
Senior Member
 
Join Date: January 27, 2012
Posts: 1,078
You sure you can't just loosen up the screws on the side to the point that you can get the metal that holds it down passed the edge of the rail and just lift it off?

I have never seen a Weaver/Picatinny rail that you couldn't. How did they get the nuts on there? Normally you can actually take nuts off the threads. (The way they were assembled)

ETA:

Looking at the pictures, you should be able to just unscrew the allen bolts from the base and take the side piece off and take the scope right straight off.

I know this can be done with the Armalite, UTG and Burris PEPR mounts (I have them), I would be suprised if it didn't work on the Nikon.

I would hate for you to spend money to fix a problem you might not have.
__________________
I am no longer participating in gun forums.

Good luck.
Crow Hunter is offline  
Old November 14, 2012, 05:50 PM   #6
Sweet Shooter
Senior Member
 
Join Date: June 17, 2011
Posts: 472
@Crow Hunter... it's the M223 with only two bolts and is a single piece unit. It doesn't have a side clamp. Attached...
Maybe I should replace the mount.

-SS-
Attached Images
File Type: jpg M223.jpg (4.1 KB, 20 views)
File Type: jpg M223_2.jpg (17.0 KB, 19 views)
Sweet Shooter is offline  
Old November 14, 2012, 06:55 PM   #7
Crow Hunter
Senior Member
 
Join Date: January 27, 2012
Posts: 1,078
Are you sure you can't back those 2 allen bolts out far enough/all the way out to the point you could get that side plate off or back far enough to just lift it right off from the top?

They had to assemble it originally and I can't think of a way you could put allen bolts in to where you couldn't get them back out.

I have never owned a Nikon M-223 mount before so I don't know for sure. But all the others that I have owned in the same price range and even lower, you could get them off.

Now if it doesn't use the piece where the allen bolts go through to clamp onto the rail, I am at a loss. How does it lock onto the rail?
__________________
I am no longer participating in gun forums.

Good luck.
Crow Hunter is offline  
Old November 14, 2012, 07:15 PM   #8
Sweet Shooter
Senior Member
 
Join Date: June 17, 2011
Posts: 472
Quote:
@Crow Hunter... Are you sure...
Very sure, the mount is one piece... there is no separate side plate. The dovetail slides on lengthways and actually requires the bolts removed to do this. There is a machined slit cut upwards running lengthways in the base which allows the two bolts to pull the two sides together to clamp around the rail... so it's actually bending them in—not that it is visible. When I mounted the scope with this mount, the mount was so precise that no windage adjustment to zero the factory zeroed crosshairs in the Nikon scope was necessary... literally shot a group less than an inch wide and high... dead nuts center.

But my Q now is do I stay with the A2 handle or go with the MBUS? Neither will be able to stay in place with the scope on, or when I wish to swap to irons. Unless I change the mount.

-SS-
Sweet Shooter is offline  
Old November 14, 2012, 07:27 PM   #9
Crow Hunter
Senior Member
 
Join Date: January 27, 2012
Posts: 1,078
Your mount doesn't come apart like this Nikon M-223 mount?

http://www.youtube.com/watch?v=5tJqvx9byz0

I am surprised if it doesn't. I thought that was how pretty much every Weaver/Picatinny mount worked and it would be odd that Nikon had 2 different designs. 2 screw vs 3 screw.

Odd.

I think I would just get another scope mount before I would start swapping BUIS. You can get a Burris PEPR mount (I just got one from SWFA) for $69.99 and you CAN take those off.
__________________
I am no longer participating in gun forums.

Good luck.
Crow Hunter is offline  
Old November 14, 2012, 07:28 PM   #10
Sweet Shooter
Senior Member
 
Join Date: June 17, 2011
Posts: 472
No it doesn't. Take a look at those pics I attached.
Also this explains.

-SS-
Sweet Shooter is offline  
Old November 14, 2012, 07:35 PM   #11
Crow Hunter
Senior Member
 
Join Date: January 27, 2012
Posts: 1,078
I can't really tell from the picture. It looks the same as the 3 screw model to me.

Its odd to me they would have swapped designs like that between the 2 and 3 screws. Kind of sounds like they are "claw" type mounts like you use on a grooved .22 receiver.

I think I would swap out to a different scope base myself.
__________________
I am no longer participating in gun forums.

Good luck.
Crow Hunter is offline  
Old November 14, 2012, 07:42 PM   #12
Crow Hunter
Senior Member
 
Join Date: January 27, 2012
Posts: 1,078
Ah. I see now. Thanks for the video.

That is annoying. I almost grabbed one of these when I picked up my last M&P15-22.

I am glad I didn't now. I don' like that at all.

I would definitely swap to a new base. Unless you could drag it off the front and get it off.

I would rather have something that had levers or at least thumbscrews that I could take off without tools so I could use the BUIS.

(I prefer Larue myself, but they are pricey)

To your original question. I would try to look through a MBUS before you buy. The sight picture isn't "clean" to me and I don't like them personally. But for BU sights, it might not really matter.
__________________
I am no longer participating in gun forums.

Good luck.
Crow Hunter is offline  
Old November 14, 2012, 07:53 PM   #13
pturner67
Senior Member
 
Join Date: February 26, 2006
Location: Fairfax, VA
Posts: 626
I'm a big fan of MBUS. I really like their redesign that has the dual aperture.

Video showing the dual aperture

http://www.youtube.com/watch?v=1C_AzdefkTM
pturner67 is offline  
Old November 15, 2012, 12:31 AM   #14
Fishbed77
Senior Member
 
Join Date: November 23, 2010
Posts: 2,421
Quote:
They are actually proved to be tougher than Troy and some other more expensive steel BUIS in some drop/impact testing that I saw
That's debatable. The MBUS has a little advantage when dropped, because it's spring-loaded nature allows it to fold and absorb the blow somewhat, but as soon as that little spring breaks, you're left with a floppy piece of junk. In the torture test you saw (if it's the same one I saw), the Troy sight survived as well, with just a minor loss of zero. My guess is that with continued testing, the Troy Folding Battlesights would last long after the MBUS crapped out.

That said, I own both. The MBUS sights are great back-up sights, but the Troys are clearly superior, if only for the vastly better sight picture. The chunky squarish rear aperture of the MBUS really wrecks the sight picture, compared with the crisp and clean Troys, which are truly good enough to be used as primary sights.

Quote:
I really like their redesign that has the dual aperture.
Unfortunately, the dual apertures on the MBUS sights (at least my example) are tough to use. You have to pry them apart with your thumbnail. Switching them in a hurry is definitely a no-go. The Troy dual apertures are much easier and quicker to use, though you have to make sure it is set back to the wide aperture before you fold them back down.

Last edited by Fishbed77; November 16, 2012 at 12:30 AM.
Fishbed77 is offline  
Old November 15, 2012, 07:22 AM   #15
madcratebuilder
Senior Member
 
Join Date: November 2, 2007
Location: Northern Orygun
Posts: 4,868
Quote:
Originally Posted by Crow Hunter
Ah. I see now. Thanks for the video.

That is annoying. I almost grabbed one of these when I picked up my last M&P15-22.

I am glad I didn't now. I don' like that at all.

I would definitely swap to a new base. Unless you could drag it off the front and get it off.

I would rather have something that had levers or at least thumbscrews that I could take off without tools so I could use the BUIS.
Nikons cost cutting measures. That is the new style mount that comes with the P223's. The original M223 mounts could be either 20moa or straight and had a tilt off mount.

One would think that a person making a youtube vid about a scope mount would know the difference between 1 inch and 30 millimeters, and that a Picitinny rail and 1913 rail are one in the same.

The OP's mount is best used with airsoft.

There are several tilt off mounts that cost the same or less than that Nikon, and are better quality. QD's are best but thumb screws well do.
madcratebuilder is offline  
Old November 15, 2012, 11:13 AM   #16
Sweet Shooter
Senior Member
 
Join Date: June 17, 2011
Posts: 472
Quote:
madcratebuilder
The OP's mount is best used with airsoft.
Airsoft! Jeeezzz it's not that bad, that's a silly statement. It's actually an amazingly precise piece of machining. And not cheap either! It would be my choice on a simple varminter for sure, it's just not a carbine scope mount.
-SS-
Sweet Shooter is offline  
Old November 15, 2012, 02:17 PM   #17
Quentin2
Senior Member
 
Join Date: June 18, 2009
Location: NorthWest USA
Posts: 1,591
I now have three rear MBUS gen 2 sights and am happy with all of them. I did get one that was defective (the hold down detent was cut wrong) but Cabelas made a quick swap with a good one.

I saw a torture test (probably the same one Crow Hunter mentioned) and the MBUS survived multiple 5' drop tests right on the extended sight with less than a 1 MOA loss of zero while Troy and Diamond were bent and had 3-5 times more loss of zero.
Quentin2 is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:20 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2013 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.12112 seconds with 10 queries