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Since I bought this Bushmaster 16" 5.56 years ago I've always run this red dot sight it came with. Shoots great with the red dot, super consistent, I can hit cans at 50 yards almost every single time.
I decided to put on these BUISs but in order to put my sight picture where the rounds go, this is how extreme my sight adjustment is. I've never had to make this extreme adjustment with my service rifles.
Anyone have any clue what's going on?
Another interesting thing is when I used a bore laser to get it close, it was nowhere close to this either.
Something seems like it's really wrong, but I can't figure out what .

PXL_20220721_045121550.jpg PXL_20220721_045112461.jpg
 
Where this really comes into play is where you are mounting your front sight. Most backup iron sights come in 2 varieties: "Gas Block" height, and "Same-Plane" height. We'll explain the difference:
The front sight you have looks to be for a gas block mount and you need a rail mount or versa visa is my guess.
BUIS sight selecting
 
The front sight you have looks to be for a gas block mount and you need a rail mount or versa visa is my guess.
BUIS sight selecting
Thanks. That would make sense, but apparently these Magpul BUIs are meant to be installed on a hand guard rail and not a gas block. In any case I've considered getting a low profile 1/4" riser to compensate but it doesn't feel right. I'm still concerned with how far my windage is adjusted as well.
 
Can you post a picture of the entire rifle laying on its side with the sights flipped up?
 
Thanks. That would make sense, but apparently these Magpul BUIs are meant to be installed on a hand guard rail and not a gas block. In any case I've considered getting a low profile 1/4" riser to compensate but it doesn't feel right. I'm still concerned with how far my windage is adjusted as well.
That is correct, Magpul MBUS sights are not made for gas block use, they would melt. However, those are not Magpul sights pictured in the OP, they are Chicom knock-off garbage. Throw them where they belong and buy some real real sights and try again.

This is what a front MBUS look like...

mag247-blk_magpul_mbus_sight_front_03_1.jpg
 
That is correct, Magpul MBUS sights are not made for gas block use, they would melt. However, those are not Magpul sights pictured in the OP, they are Chicom knock-off garbage. Throw them where they belong and buy some real real sights and try again.

This is what a front MBUS look like...

View attachment 1248447
Gotta go with the peak sights. But those aren't 10.00
 
That is correct, Magpul MBUS sights are not made for gas block use, they would melt. However, those are not Magpul sights pictured in the OP, they are Chicom knock-off garbage. Throw them where they belong and buy some real real sights and try again.

This is what a front MBUS look like...

View attachment 1248447
I guess I got scammed then, they came in a Magpul box. I bought these years ago it just took a while until I felt like sighting them in. I would still like to know what is going on physically that explains why they don't seem to line up.
It's like working on cars, people often throw parts at a problem without actually diagnosing what's wrong, or blaming something on inferior quality but there's more going on than that. I got a lot of good insight here though, thanks everyone for the responses.
 
If by some miracle the junk sights are not grossly misaligned, it may have something to do with handguard attachment.

E.g. the first time I installed a Centurion c4 rail, it had a directional bias from the barrel nut and the front sight was off. Then I installed it more methodically and correctly, and the problem was fixed.
 
If by some miracle the junk sights are not grossly misaligned, it may have something to do with handguard attachment.

E.g. the first time I installed a Centurion c4 rail, it had a directional bias from the barrel nut and the front sight was off. Then I installed it more methodically and correctly, and the problem was fixed.
The handguard slips behind the spring loaded barrel ring then the two halves bolt together. There are marks on the inside of the hand guard where it clamps on to the barrel nut, but nothing seems visually out of line when all installed. I would think with roughly 8mm of threads out on the elevation sight something would be visually apparent if something wasn't installed properly?
The top half of the hand guard has a notch that fits well around the gas tube.

PXL_20220729_145602879.jpg
 
Yeah that's likely part of the problem.

It may look straight enough but it's generally not a great idea to mount sights on a non free float, drop-in kind of rail. They just aren't that precise or stable. Look at the size of the barrel nut on Geissele or any of the Wedge-Lock (MEGA/Zev, Hodge, Triarc) handguards and how the rails interface with them, and then compare them to your setup.

E.g..

_SHOT_Show_2013_David_Crane_DefenseReview.com_DR_1.jpg
 
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