Confused on Front Sight Height

[Chief TC]

OK, I am thoroughly confused. I took my M1903A3 out to figure out the POI at 200yds in the 200 yd sight setting with my load I know are very accurate. My POI was too low so I filed my front sight to raise POI. But POI went lower. I am not a math guy, so I am wondering what happened? the lower the front sight the higher the POI, correct?

 

[CoalCrackerAl]

Front site up to lower. Rear up to raise. Or rear down to lower.

 

[MEHavey]

he lower the front sight the higher the POI, correct?

Correctomundo . . .

 

[JohnKSa]

A shorter front sight will make the gun shoot higher. A taller front sight will make the gun shoot lower.

If you filed your front sight shorter and the POI dropped on target, then something else must have changed.

 

[Dave DeLaurant]

You didn't change ammo, shoot on a colder day or jog the rear sight by any chance? Also, when you filed the front sight, might you have also altered the bedding of the barrel in the stock?

You're basic idea was correct: lowering the front gives a higher POI.

 

[DustyRusty]

OK, I am thoroughly confused. I took my M1903A3 out to figure out the POI at 200yds in the 200 yd sight setting with my load I know are very accurate. My POI was too low so I filed my front sight to raise POI. But POI went lower. I am not a math guy, so I am wondering what happened? the lower the front sight the higher the POI, correct?

Attached is a PDF file with a nice article about the sights. Not mine, but I found it somewhere.
When I had to shoot mine at Camp Perry, I found reliable repeatable GI ammo to use, got a zero at 200 yards and glyptol'ed the rear slide into position.

 

[Chief TC]

You didn't change ammo, shoot on a colder day or jog the rear sight by any chance? Also, when you filed the front sight, might you have also altered the bedding of the barrel in the stock?

You're basic idea was correct: lowering the front gives a higher POI.

Thanks Dave and others here too. Same loads, so no ammo change. I think you may be right on the stock and I wasn’t using my normal bench rest bag. I need to reassess and evaluate. I must say, getting this milsurp into shape is really challenging my patience. I had to invest a lot of time and effort in a lot of other old milsurps but this one is unusually difficult. I know it is an MOA shooter but there are things that keep changing and moving on it. I need to reset the action screws and barrel bands. Basically, I got the right load but need to achieve consistency. Thanks again.

 

[Chief TC]

Attached is a PDF file with a nice article about the sights. Not mine, but I found it somewhere.
When I had to shoot mine at Camp Perry, I found reliable repeatable GI ammo to use, got a zero at 200 yards and glyptol'ed the rear slide into position.

This is great Dusty. Thanks so much.

 

[HEAVY METAL 1]

You need to move the rear sight in the direction you want the impact on target to be or move the front sight the opposite of where you want the impact to be. I have been shooting open sighted milsurps for ~25 years and burned that one in my brain long ago.

 

[unspellable]

Thanks Dave and others here too. Same loads, so no ammo change. I think you may be right on the stock and I wasn’t using my normal bench rest bag. I need to reassess and evaluate. I must say, getting this milsurp into shape is really challenging my patience. I had to invest a lot of time and effort in a lot of other old milsurps but this one is unusually difficult. I know it is an MOA shooter but there are things that keep changing and moving on it. I need to reset the action screws and barrel bands. Basically, I got the right load but need to achieve consistency. Thanks again.

wasn’t using my normal bench rest bag

 

[JohnKSa]

Yup. If you use a hard front rest, you can get fore end bounce that will open up groups and generally cause the shots to go higher on the target.

 

[Chief TC]

Update. Finally made sure I had all my gear and got the M1903A3 completely dialed in. Was able to shoot sub 2 MOA at 300 meters. Not having my bag rest really messed me last outing. Lesson learned! Thanks everyone.