Magpul MBUS sights beware

[cmgee67]

I own a few sets of the polymer Magpul mbus flip up sights and they have always worked well for me. While out shooting two weeks ago I noticed that on the AR that I was shooting, the rear sight had a pin that was starting to walk out. It’s the long pin on the part of the sight that doesn’t flip up. I pushed it back in and the sight never lost zero. I have never had this happen on the others that I own so I decided to just JB weld the ends of the pin to the sight itself so they can’t walk out. I thought I’d pass the info along. That way you can keep an eye out on yours if you use them.

[cmgee67]

Yes sir that is the Pin. I have never had it happen until then. JB weld on the ends have fixed the problem.

[Maxwell]

Speaking of sights:
Why is the line-of-sight on modern AR sights so far above the receiver/Barrel line?
Wouldn't they be more accurate if lower and more in line with the barrel?



Max

[jsenner]

Where did you get them?

There was a run of Chinese fakes of these exact sights a while ago and they were VERY well faked, you couldn't tell them apart packaging and all. They all had a very common problem, those pins would work out of the body. The springs in the sights were ever so slightly lighter in color as well.

I've had to replace half a dozen of them on different guns for folks that got the fakes - all of them had those pins walk out like that.

[Pawpaw]

Speaking of sights:
Why is the line-of-sight on modern AR sights so far above the receiver/Barrel line?
Wouldn't they be more accurate if lower and more in line with the barrel?

Because the rifle uses an in-line stock, the sights have to be raised or you won't be able to get your eye behind them. The in-line stock, aside from being necessary to the design's function, does a lot to mitigate muzzle rise. If the stock had a drop to it, like a traditionally stocked rifle, the sights can be mounted lower, but muzzle rise increases.

The higher sights do not affect accuracy. Failing to keep the rifle level when firing will throw the sights & bore out of vertical alignment, resulting in less than optimal results.

[The Annoyed Man]

Speaking of sights:
Why is the line-of-sight on modern AR sights so far above the receiver/Barrel line?
Wouldn't they be more accurate if lower and more in line with the barrel?

Because the rifle uses an in-line stock, the sights have to be raised or you won't be able to get your eye behind them. The in-line stock, aside from being necessary to the design's function, does a lot to mitigate muzzle rise. If the stock had a drop to it, like a traditionally stocked rifle, the sights can be mounted lower, but muzzle rise increases.

The higher sights do not affect accuracy. Failing to keep the rifle level when firing will throw the sights & bore out of vertical alignment, resulting in less than optimal results.

What he said.

[C-dub]

Speaking of sights:
Why is the line-of-sight on modern AR sights so far above the receiver/Barrel line?
Wouldn't they be more accurate if lower and more in line with the barrel?

Because the rifle uses an in-line stock, the sights have to be raised or you won't be able to get your eye behind them. The in-line stock, aside from being necessary to the design's function, does a lot to mitigate muzzle rise. If the stock had a drop to it, like a traditionally stocked rifle, the sights can be mounted lower, but muzzle rise increases.

The higher sights do not affect accuracy. Failing to keep the rifle level when firing will throw the sights & bore out of vertical alignment, resulting in less than optimal results.

What he said.

What they said.

Accuracy depends on the rifle, the shooter, and whether or not the sights are correctly "sighted". Not location of the sights. That's my non-expert humble opinion and it's worth what you paid for it.

[warnmar10]

Speaking of sights:
Why is the line-of-sight on modern AR sights so far above the receiver/Barrel line?
Wouldn't they be more accurate if lower and more in line with the barrel?

Because the rifle uses an in-line stock, the sights have to be raised or you won't be able to get your eye behind them. The in-line stock, aside from being necessary to the design's function, does a lot to mitigate muzzle rise. If the stock had a drop to it, like a traditionally stocked rifle, the sights can be mounted lower, but muzzle rise increases.

The higher sights do not affect accuracy. Failing to keep the rifle level when firing will throw the sights & bore out of vertical alignment, resulting in less than optimal results.

What he said.

What they said.

Accuracy depends on the rifle, the shooter, and whether or not the sights are correctly "sighted". Not location of the sights. That's my non-expert humble opinion and it's worth what you paid for it.

I agree with what C-dub Johnson said about what Annoyed Johnson said about what Pawpaw Johnson wrote.

[warnmar10]

Where did you get them?

There was a run of Chinese fakes of these exact sights a while ago and they were VERY well faked, you couldn't tell them apart packaging and all. They all had a very common problem, those pins would work out of the body. The springs in the sights were ever so slightly lighter in color as well.

I've had to replace half a dozen of them on different guns for folks that got the fakes - all of them had those pins walk out like that.

If it takes a metric allen wrench to tighten the screws it is probably a fake.

[Maxwell]

My thanks to the Almighty Johnsons!

By accuracy I meant that with lower sights there would be less of an arc in trajectory, so bullet drop would be easier to compensate for. I do know and understand that with any shot there will be a convergence point where line of sight meets bullet trajectory, a distance after that where the bullet would actually hit the target higher than line of sight, and a point where it comes back down to line of sight and continues to drop after that.

I was just thinking that lowering the angle of intersection would flatten out the arc.

[Odiferous]

That height above bore has also contributed to the untimely demise of many a chronograph. Just gotta be aware of it with AR platforms.

[cmgee67]

I assure you the sights are not fake. I bought them from academy....

[lfinsr]

My thanks to the Almighty Johnsons!

By accuracy I meant that with lower sights there would be less of an arc in trajectory, so bullet drop would be easier to compensate for. I do know and understand that with any shot there will be a convergence point where line of sight meets bullet trajectory, a distance after that where the bullet would actually hit the target higher than line of sight, and a point where it comes back down to line of sight and continues to drop after that.

I was just thinking that lowering the angle of intersection would flatten out the arc.

I'm hoping you just chose your words poorly. Bullet arc is a factor of gravity, changing sights will make no difference.