Rear sight adjustment, A little help please

To move the point of impact to the right you move the rear sight to the right. The amount you have to move it can be approximated by comparing the distance between front and rear sights and the distance to the target. If the distance between sights is 6 inches and the distance to the target is 252 inches (7 yards) then you have to move the rear sight 6/252 inches or 1/42 inches per inch you want to move the point of impact.
 
Make sure you use a brass or nylon punch to keep from damaging your sight. A copper removing solvent will get rid of brass marks.
 
Sight correction fomula is as follow;

C = (D/R) X S where;

C = Movement (correction) needed in inches

D = Impact deviation of the bullet, in inches
R = Range, in inches
S = Sight Radius

So, say;

R = 7 yards, (X36) = 252 inches
D = impact deviation; 5 inches (average)
S = Sight Radius (unklnwon but will assume 5 inches)

S0 C = (5/252)X5 = 0.099"
 
I have a small portable plastic vise that I bring to the range when I sight in. Clamp it to the bench, put the slide in the padded jaws and tap with a brass punch and hammer. Do it until it shoots to POA.
 
Before you do that you may want to look into the handgun shooter's circle of issues and corrections. It's hard to believe that the previous owner tolerated it shooting that far off for so long so it's possible that you're not fully in tune with what sort of trigger finger positioning you need for this gun. I know that if I mess up my trigger finger positioning on my CZ or my 1911 it can easily result in my groups being offset by a similar amount to what you're getting. The grouping is still decent but it's just over there instead of on target. Each gun has it's own needs for the trigger finger.

Testing from a rest would also help in evalutating whether it's the sights or how you're holding the gun. When I run into issues like this with a new handgun shooting from a rest is the first thing I do so I minimise any grip or trigger finger pulling issues. If it's still off by the same amount then I can be better assured that it's the gun and not me.
 
Unless you use a caliper to measure the .024 inch movement then it's a tap and try thing. Move it about the width of a narrow pencil line and go shoot it. If it's still out adjust some more and try again.

I'd still suggest you bench rest it first to see if it's the sights or you though. New guns almost always surprise me and I have to adjust my grip or amount of trigger finger to find their sweet spot. Out of 13 I've got only three finally ended up being the sights. And one of those had loose screws holding the sight in place so it was walking around.
 
You must log in or register to reply here.
Back
Top Bottom