Rear sights

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g.man
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Rear sights

Post by g.man »

What are the distance increments of the rear sights. I have a 45/70
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Re: Rear sights

Post by Ranch Dog »

g.man wrote:What are the distance increments of the rear sights. I have a 45/70
It would some measure of "minute of angle" but not distance.
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Re: Rear sights

Post by g.man »

Thank you but still alittle confused by your answer. Can you explain your answer? Thanks
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Re: Rear sights

Post by zippy »

g.man wrote:What are the distance increments of the rear sights. I have a 45/70
I was curious about the effect of the Rossi sight elevator also. Mine has been left at the lowest setting, and has been perfect for the distance I shoot. I took your question as an excuse to lay out the geometry for my own curiosity.

My measurements were taken from a one year old 24" oct. barrel .357 Rossi 92.
Measurements were eyeballed using 1/32" rule, not calipers, so its marginally accurate.
4 elevator steps gave me 5/32" gain so .04" per step.
Front of rear sight to front sight bead (Sight Radius) dimension, 21 3/8".

These parameters for the 24" barrel equate to roughly .108 degrees change per step, or 6.5 MOA (minute of angle).
Roughly 6.7" change to POA ( point of aim ) at 100 yards, per step.

Extrapolated to a 20" barrel by moving front sight dim 4" closer, to 17 3/8".
Roughly .132 degrees change, or 8 MOA, per step.
Roughly 8.25" change to POA at 100 yards, per step.

Extrapolated to 16" barrel by moving front sight dim 8" closer, to 13 3/8".
Roughly .172 degrees change, or 10 MOA, per step.
Roughly 10.73" change to POA at 100 yards, per step.

I don't know if your configuration is dimensionally similar but this might be helpful as a starting point. Combined with a ballistic profile chart of your ammo, you should have a pretty good idea of point of impact.
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Re: Rear sights

Post by zippy »

Had to edit my calcs, as my initial POA figures were based on 100 feet, not yards. Hubble Telescope error. :oops:


Minute of angle: A Minute of Angle (MOA) is an angular measurement. A MOA is 1/60th of a degree. 1 MOA spreads about 1" per 100 yards. ( actually 1.047") 1 MOA is a different size at different distances, 8" at 800 yards is still just 1 MOA.
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Re: Rear sights

Post by g.man »

Thank you
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Re: Rear sights

Post by zippy »

g.man wrote:Thank you
Your welcome.

Did that answer your question?
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