Lyman GPR shooting high ?

[GregC]

My GPR is shooting about 8" high at fifty yards and my sights are out of adjustment. I installed the lyman adjustable sights on the gun. The rear sight is all the way Up and the front sight has no adjustment.

Was shooting 80 grains FFFG and dropped back to 70 grains with not much difference in POI.

Gonna try some FFG and see what that does. Any other suggestions?

 

[watmoc]

move the rear sight in the direction you want the ball to go. Move it down.

 

[jethro224]

Yep. Move the rear sight down.

 

[cowpoke1955]

Agree with the others. Move the rear sight all the way down and start over.

 

[catman]

The rule is you move the rear sight in the direction you want the ball to move.
Raise the rear sight raises the place the ball hits.
Lower the rear sight lowers the place where the ball hits.
Move the rear sight left to move the place the ball hits left etc.

Now the front sight is just the opposite.
Moving the front sight to the left moves the place the ball hits to the right.
Filing the front sight down raises the place the ball hits.
I'd say raising the front sight lowers where the ball hits but raising a front sight is kind of like cutting a short board longer.

 

My GPR is shooting about 8" high at fifty yards and my sights are out of adjustment. I installed the lyman adjustable sights on the gun.

You answered your own question. When installing new sights, they need to be adjusted.

 

[GregC]

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

 

[Billnpatti]

The reason you are shooting high is that your rear sight is all the way up. Move it down and your POI will go down as well. When adjusting your sights, always move the rear sight in the direction that you want to move your POI. In most cases when you have an adjustable rear sight, you will adjust your POI vertically using your rear sight and will adjust your windage using your front sight. When adjusting your front sight, move it in the direction opposite the way you want to move your POI.

The formula for adjusting your sights is simple. First, you measure the distance in inches that you want to move your POI and write that down. Then measure the distance from your front sight to your rear sight in inches and write that down. Now you need to figure the distance in inches from your front sight to the target. For 50 yards, that would be 1800 inches. Now, divide the distance from your front to your rear sight by the distance to the target. Since I don't know what this number is for your rifle, I will designate this number as "X". The formula then becomes X/1800. Next multiply this number by the distance you want to move your POI. In your case, this is 8 inches. We now have X/1800 times 8 which can be expressed as 8X/1800. The answer that you get will be a fractional number. If you multiply this fractional number by 1000, you will end up with the number of thoundths of an inch to move your rear sight down.

My rifle has a known distance of 26 inches from the rear sight to the front sight so lets do the math using that figure. We will have 8 X 26/1800. This gives us 0.1155555.... We can round this off to 0.116. When we multiply this number by 1000 we have 116. This means that to move our point of impact 8 inches down at 50 yards, we will need to move our rear sight down 116 thousandths of an inch or slightly less than 1/8 of an inch down. This is just an example and you will have to use your own measurements to adjust your rifle's sight.

I hope this all makes sense to you and you find it helpful. Good luck and good shooting. :thumbsup:

 

[biliff]

What am I missing?

You left out the line of the bore and the target. By forcing the line of sight down you have to raise the line of the bore to bring the sights back on the target.

 

[Claude Mathis]

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

For starters, a see-saw has no sights. :wink:

When you raise the rear sight, you are lowering the rear of the barrel, relative to your line of sight.

Move the rear sight in the direction you want the bullet to go. We're not saying move the rear of the barrel, as in your see-saw example.

 

[renovato]

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

Raising the rear sight is the equivelent of lowering the front sight.
Lowering the front sight is the equivelent of raising the muzzle.
Raising the muzzle causes the shots to hit higher in relation to the point of aim.

 

[jethro224]

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

Think of your see-saw sitting perfectly level. Now lay a piece of 2x4 at each end to simulate sights.
Now lay a 2nd chunk of 2x4 on top of the left one to simulate raising the rear sight.
Adjust the see-saw so that the "sights" are again perfectly level. You will have to lower the left end. See where the see-saw is pointing?

 

[GregC]

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

Raising the rear sight is the equivelent of lowering the front sight.
Lowering the front sight is the equivelent of raising the muzzle.
Raising the muzzle causes the shots to hit higher in relation to the point of aim.

Aren't you contradicting everyone else and agreeing with me???

 

[Semisane]

Please excuse my rudimentary drawing skills.

 

[rafterob]

I was about to say "someone draw this guy a picture"- hopefully that will do it for him. :hatsoff:

 

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

Raising the rear sight is the equivelent of lowering the front sight.
Lowering the front sight is the equivelent of raising the muzzle.
Raising the muzzle causes the shots to hit higher in relation to the point of aim.

Aren't you contradicting everyone else and agreeing with me???

Forget your see saw and listen to everyone. MOVE THE REAR SIGHT IN THE DIRECTION YOU WANT THE BULLET TO GO!

If you cannot achieve what you want by moving the rear sight, then, MOVE THE FRONT SIGHT IN THE OPPOSITE DIRECTION THAT YOU WANT THE BULLET TO GO!

 

[mykeal]

This makes no sense to me. Think of a seasaw in a play ground. The rear sight is the left and the front sight is the right.

By raising the left side (rear sight) you would force the front sight (or muzzle) lower thus lowering the point of impact.

What am I missing?

Raising the rear sight is the equivelent of lowering the front sight.
Lowering the front sight is the equivelent of raising the muzzle.
Raising the muzzle causes the shots to hit higher in relation to the point of aim.

Aren't you contradicting everyone else and agreeing with me???

No, he's not. Read it carefully. He said,

Raising the rear sight...causes the shots to hit higher.

Conversely, lowering the rear sight ...causes the shots to hit lower.
You want the shots to hit lower.
Therefore, lower the rear sight.

 

[tg]

I would put the primitive sights on and get a file out of the tool box and get the sights where you want them and they will stay there.usually you will be shooting low and you just have to file down the front site to bring it to where you want.

 

[FishDFly]

In honesty, have you read the manual with the rifle, it might help?

RDE

 

[ohio ramrod]

This conversation reminds me of the time I was adjusting my rear sight for windage using a depth mic to measure adjustments. The stem on the depth mic was loose and I was not getting a true reading. I went back to drawing pictures and was about ready to bend the barrel until I noticed the mic was loose.I tightened the mic and sighted the rifle in with five shots.Never to old to learn!