New front sight for 4.5" Smith 25-2

[ezekiel38]

Recently purchased a Smith 25-2 45 ACP. Gun is a mild custom with a Smith ramp front sight and sight is pinned in. Front sight has been filed on and is .175" in height. Gun shoots 1 foot high at 50 ft using standard hard ball loads. This is with the rear sight bottomed out. Appears to be a midheight rear sight.

My go to load for this gun will be a Montana Bullet Works SWC 215 grain cast at or near 900FPS. Going to leave the rear sight alone as I have gotten the white paint off the rear of the blade and the sight is clean and it moves freely now. Should I go .250 or .275 for a Patridge type black sight?

Like to hear from someone who knows more about this than I do, (Which that statement should create many responses.) This is just a paper puncher and can bouncer.

TIA

[squigz]

I'm not sure I know more about it that you do. But the calculation is amount of error (12 inches) multiplied by sight radius (you have to fill in that blank as I don't have a 25-2) divided by distance to the target (600 inches [for 50 feet from target]).

That would give you what sight height you would need where your current amount of error is happening, assuming you're leaving the rear sight bottomed out. If you want to run it in the middle of the rear sight adjustment range, find out where the bullet is impacting in that range, and then re-run the calculation with the adjusted error amount.

[bradshaw]

“.... Smith 25-2 45 ACP.... Smith ramp front sight and sight is pinned in. Front sight has been filed on and is .175" in height. Gun shoots 1 foot high at 50 ft using standard hard ball loads.”
----ezekeil38

*****

POI (Point of Impact) 1’ high @ 50’ calls for new from sight. Nothing else will do. To figure how much taller a new front sight must be, the formula is ERROR X SIGHT RADIUS divided by DISTANCE to TARGET. All calculations in inches.

Example
* ERROR (in this case 12-inches) x SIGHT RADIUS (example 6.25-inches) = 75.

* Divide by DISTANCE to TARGET (50’= 600-inches.).

* Thus, 12” x 6.25” = 75”.
75” divided by 600” = SIGHT ADJUSTMENT .140-inch.

Sight radius is the measurement between front & rear sight, as seen by eye. Write the formula down a nail it on the wall. It works for all iron sights, handgun and rifle.
David Bradshaw

[ezekiel38]

Thank you this formula will be printed out and go in my gun bag and posted on my reloading room wall. This saves multiple hours of "head scratching". Thanks to you both for your help.