Magpul Pro LR sight radius and adjustment

[ace4059]

I was wondering if anyone has and experience with the Magpul Pro LR sight on extended sight radius.

Per magpuls website:
WINDAGE ADJUSTMENT
~0.5 MOA (0.566"/100m) per click with a 14.5" sight radius
~0.4 MOA (0.410"/100m) per click with a 20" sight radius

*NOTE: The 200-600 m elevation adjustment wheel is a hybrid calibration taking into consideration CALIBERS (5.56 and 7.62 NATO), CARTRIDGES (M855, M193, Mk262, TSX 55gr, M80, M118LR), BULLET WEIGHTS (55-77gr for 5.56 and 147-175gr for 7.62), BARREL LENGTHS (14.5-20"), SIGHT RADIUS (14.5-20" for 5.56 and 18-20" for 7.62), POINT OF IMPACT DISCREPANCY (+2.5" to -5.0"), and assuming standard temperature and pressure.

My sight radius will be 22”
18” 556 barrel with a 17” BCM rail.

Does anyone have a calculation as far as the windage and more importantly the elevation?
Also wonder with the extra 2” if a 55 gr 62gr 69 gr or 77 gr would be closer to the elevation POA and POI.

Or it could all be irrelevant and still within magpuls guide lines.

Thoughts?

[Joe Mamma]

I was wondering if anyone has and experience with the Magpul Pro LR sight on extended sight radius.

Per magpuls website:
WINDAGE ADJUSTMENT
~0.5 MOA (0.566"/100m) per click with a 14.5" sight radius
~0.4 MOA (0.410"/100m) per click with a 20" sight radius

*NOTE: The 200-600 m elevation adjustment wheel is a hybrid calibration taking into consideration CALIBERS (5.56 and 7.62 NATO), CARTRIDGES (M855, M193, Mk262, TSX 55gr, M80, M118LR), BULLET WEIGHTS (55-77gr for 5.56 and 147-175gr for 7.62), BARREL LENGTHS (14.5-20"), SIGHT RADIUS (14.5-20" for 5.56 and 18-20" for 7.62), POINT OF IMPACT DISCREPANCY (+2.5" to -5.0"), and assuming standard temperature and pressure.

My sight radius will be 22”
18” 556 barrel with a 17” BCM rail.

Does anyone have a calculation as far as the windage and more importantly the elevation?
Also wonder with the extra 2” if a 55 gr 62gr 69 gr or 77 gr would be closer to the elevation POA and POI.

Or it could all be irrelevant and still within magpuls guide lines.

Thoughts?

I am far from an expert. However, regarding windage adjustments, you can do a reverse calculation the figure out sight movement per click using the numbers you quoted from Magpul. Then using the sight radius you provided for your gun, you can figure out the point of impact change at a particlar distance. So using the numbers in your post, my calculation says one windage click on your gun would move the point of impact about 0.373" at 100 meters.

I would not take that number too literally because I think one "real world" factor is the position of the sights (how far forward or rearward they are) relative to the muzzle of the barrel (on your gun and Magpul's test gun). If you know what the thread pitch really is on your gun, and how many clicks per rotation, that would make this calculation more exact. However, it would still be theoretical (in my opinion).

Regarding elevation, I don't know exactly how the Magpul LR sight works, so I don't know the thread pitch or how much the rear sight moves with each adjustment click. It might also move a different amount per adjustment click depending on the distance to target. If you can get that information or determine it yourself, I or someone else here can probably do the calculations to determine point of impact changes per adjustment click at various distances.

I hope this helps.

Joe Mamma

[masakari]

I was wondering this myself. Mine are on a 5.56 rifle with 16" barrel and 15" rail, mounted at the rear of the receiver and front of the rail.

[GH41]

I was wondering if anyone has and experience with the Magpul Pro LR sight on extended sight radius.

Per magpuls website:
WINDAGE ADJUSTMENT
~0.5 MOA (0.566"/100m) per click with a 14.5" sight radius
~0.4 MOA (0.410"/100m) per click with a 20" sight radius

*NOTE: The 200-600 m elevation adjustment wheel is a hybrid calibration taking into consideration CALIBERS (5.56 and 7.62 NATO), CARTRIDGES (M855, M193, Mk262, TSX 55gr, M80, M118LR), BULLET WEIGHTS (55-77gr for 5.56 and 147-175gr for 7.62), BARREL LENGTHS (14.5-20"), SIGHT RADIUS (14.5-20" for 5.56 and 18-20" for 7.62), POINT OF IMPACT DISCREPANCY (+2.5" to -5.0"), and assuming standard temperature and pressure.

My sight radius will be 22”
18” 556 barrel with a 17” BCM rail.

Does anyone have a calculation as far as the windage and more importantly the elevation?
Also wonder with the extra 2” if a 55 gr 62gr 69 gr or 77 gr would be closer to the elevation POA and POI.

Or it could all be irrelevant and still within magpuls guide lines.

Thoughts?

I am going to assume Jo Mamma's math is correct. I don't see how 27 thou difference (the thickness of 2 business cards) could be even slightly relevant in the real world. Not like you are taking folding sights to Camp Perry.

[ace4059]

I am going to assume Jo Mamma's math is correct. I don't see how 27 thou difference (the thickness of 2 business cards) could be even slightly relevant in the real world. Not like you are taking folding sights to Camp Perry.

It will give you finer adjustment. Instead of 1/2 MOA adjustment per click it will give you 1/3 MOA adjustment per click. But I agree that’s irrelevant.

The main thing is the elevation dial and if it will even be close to the setting.