? about PISTOL sights: high vs. low

[Widder, SASS #59054]

I have a semi auto Pistol with a very high front site and very high rear sight.

BOTH sights are the same height.

 

The Pistol shoots POA is also POI, which works good for me.

 

QUESTION:  If BOTH of the HIGH sights are the same height, will the POA still produce POI if BOTH sights are lowered the same?

 

To help with my inquiry, I use the sights basically recommended by manufacturers with the top of the front sight being level with the top

of the rear sight.

 

Thanks.

 

..........Widder

 

[Subdeacon Joe]

If I have my geometry right (somewhat doubtful) lowering the sights will cause the point of aim to intersect the trajectory at a point closer to the muzzle. 

 

 

Maybe this one is a better illustration:

If you make distance d smaller then the LOS intersects the reference line closer to the gun.

 

 

[Pat Riot]

If both are lowered the same you should be fine. I wonder if you have “suppressor sights” on the gun. Are they enough to use the sights with a suppressor, do you think?

 

Also, is the gun designated with an “MOS”?  Modular Optic System”...is there a slide cutout for a reflex sight to be installed?

[The Original Lumpy Gritz]

2 minutes ago, Pat Riot, SASS #13748 said:

If both are lowered the same you should be fine. I wonder if you have “suppressor sights” on the gun. Are they enough to use the sights with a suppressor, do you think?

This X 2

OLG 

[ShadowCatcher]

Generally speaking sights are set up to result in the barrel pointing up above horizontal when you shoot.  That's because

the bullet starts dropping immediately due to gravity, so we need to launch it upwards in a parabolic arch to intersect the

target at some pre-determined range. The sights may be the same height relative some part of the gun, but you can be

pretty sure that the front sight is lower than the rear sight relative to the centerline of the bore axis, resulting in a tip up.

 

So it depends on how much you take off and where.  If you remove the same amount of height from each, there should be

no change in POI, because there is no change to the angle between the sight plane and the bore centerline. 

If you take metal off the front sight, the bullet impacts higher at the same range, and likewise if you take

height off the rear sight it lowers the POI at the same range.

 

There are sight calculators available to tell you how much to remove based on POI, but they assume you are only removing or

adding height to one sight.

 

There are a number of guns on the market that come with suppressor friendly sights, tall enough to see over the can, and

also with the advent of pistol red-dot sights there are some folks making sights that are coincident with the red-dot so that they

are both use-able without any adjustments (after zeroing) in the event of battery failure.  If yours is one of those you

can research the factory stock sights to see what height they use for them.

 

Likewise Brownells and Dawson Precision have sights and can give you a recommended sight height to use. 

 

HTH

 

SC

[Crooked River Pete, SASS 43485]

21 minutes ago, ShadowCatcher said:

Generally speaking sights are set up to result in the barrel pointing up above horizontal when you shoot. 

That may be true with rifles, but I've noticed with hand guns the front sight is higher than the back sight. This causes the barrel to point down when sighting and recoil brings it back up. Check your SAA and see if it doesn't point down when the sights are level.

[Widder, SASS #59054]

Thanks for all the replies.

 

I mic'd both sights and they are both .402

 

Yes, it is factory set up for a red dot sight system, and I may put a Holosun GR dot on it.   I like green better than red.

 

..........Widder

 

[Three Foot Johnson]

7 hours ago, Widder, SASS #59054 said:

I have a semi auto Pistol with a very high front site and very high rear sight.

BOTH sights are the same height.

 

The Pistol shoots POA is also POI, which works good for me. At what range? Gravity dictates there will be only two ranges where POI = POA. The line of sight is pointed downward from the line of the bore, so the bullet appears to rise - impossible, of course - but the bullet's trajectory will intersect the sight line in two places, once "going up" and once "going down".

 

QUESTION:  If BOTH of the HIGH sights are the same height, will the POA still produce POI if BOTH sights are lowered the same? No. Your line of sight is pointing down in relation to the line of the bore. If you lower both sights the same distance, let's greatly exaggerate the distance and say 2' above and below the line of the bore, with the lines of sight remaining parallel to each other, obviously the point of impact is going to change greatly from the old point of aim. If your line of sight is exactly parallel to the bore line, the point of impact will rise at the same rate as the point of aim is moved closer to the bore line. The bullet begins to be drawn down by gravity as soon as it exits the bore. Let's exaggerate here again - if the bullet strikes the target exactly at the point of aim, and you lower each sight 4', everything else being equal, the point of impact will be higher by 4' because the entire firearm will have to be raised 4' to get the sights on target. Your point of impact, of course, is now 4' higher. 

 

 

 

[Widder, SASS #59054]

Three Foot,

barrel is 4" long.   Shooting distance is 10 yds.

 

..........Widder

 

[Subdeacon Joe]

9 minutes ago, Widder, SASS #59054 said:

Three Foot,

barrel is 4" long.   Shooting distance is 10 yds.

 

..........Widder

 

 

The concept stays the same. 

[Noz]

Now, Three Foot. You know the bullet from a 270 will rise very gently until it gets about 300 yards out then it will flatten out a bit!

[Widder, SASS #59054]

23 minutes ago, Noz said:

Now, Three Foot. You know the bullet from a 270 will rise very gently until it gets about 300 yards out then it will flatten out a bit!

 

And a lot of that is determined by how hard the shooter pulls the trigger..... 

 

Everybody knows the harder you pull the trigger the faster the bullet goes.

 

..........Widder

 

[Injun Ryder, SASS #36201L]

7 minutes ago, Widder, SASS #59054 said:

 

And a lot of that is determined by how hard the shooter pulls the trigger..... 

 

Everybody knows the harder you pull the trigger the faster the bullet goes.

 

..........Widder

 

 

And... If it is a handgun, pushing the gun forward when firing will also increase the velocity!

[ShadowCatcher]

9 hours ago, Crooked River Pete, SASS 43485 said:

That may be true with rifles, but I've noticed with hand guns the front sight is higher than the back sight. This causes the barrel to point down when sighting and recoil brings it back up. Check your SAA and see if it doesn't point down when the sights are level.

physics is physics.

 

[Crooked River Pete, SASS 43485]

10 hours ago, ShadowCatcher said:

physics is physics.

Yes it is, recoil is part of those physics. Get out your SAA lay a straight edge on top of the sights, you'll see the bore runs down from line of sight.

[ShadowCatcher]

1 hour ago, Crooked River Pete, SASS 43485 said:

Yes it is, recoil is part of those physics. Get out your SAA lay a straight edge on top of the sights, you'll see the bore runs down from line of sight.

That is true on any firearm that has recoil.  The angle of the line formed by the sights and the angle of the bore axis are

rarely if ever parallel.  Rifles included. 

 

Having a longer sight radius and more massive firearm will reduce the apparent effects of recoil, the the physics is the same for both.  It's easier to

see on a 2lb pistol with a 6" sight radius compared to a 7 lb rifle with a 28" sight radius, but it works the same.

[Marshal Mo Hare, SASS #45984]

is the gun for personal protection? The difference won’t amount to a bean, let alone a hill of beans

[J-BAR #18287]

If you have a handgun with fixed sights that hits POI at POA,  don’t do nothing and buy a lottery ticket and say a prayer of thanks.

 

Change something?  Are you kidding me??

 

[Badger Mountain Charlie SASS #43172]

On 11/22/2020 at 3:40 PM, Widder, SASS #59054 said:

 

And a lot of that is determined by how hard the shooter pulls the trigger..... 

 

Everybody knows the harder you pull the trigger the faster the bullet goes.

 

..........Widder

 

Does pulling the trigger harder also increase the impact at terminal impact?

[Widder, SASS #59054]

7 hours ago, Marshal Mo Hare, SASS #45984 said:

is the gun for personal protection? The difference won’t amount to a bean, let alone a hill of beans

 

Marshal,  that is a great question.   Yes, mostly for personal protection and hitting the target at 50' and less.

 

..........Widder

 

[Tennessee williams]

   With a handgun the bore line generally is angled down relative to the sight line to negate the muzzle rise. Usually a short barrel will have a taller front sight and thus a steeper angle. To check this, insert a properly sized dowel rod into the muzzle and lay another dowel rod on your sights. You will see the angle then...

That being said if BOTH front and rear sights are altered the SAME you are not changing any angles and at 10 yards you're not worried about bullet trajectories.

Look at it like this...that bullet is going to travel the same out of the muzzle regardless of where your sights are. The only difference is you will raise your pistol up 1/4" higher if you lower your sights 1/4".

I used to shoot some long range silhouette with a 686 that had adjustable front and rear sights. One click on the front sight was equal to one half of the total elevation of the rear sight if memory serves. Moving both up or both down had a net zero affect. .2 of a grain of powder off in the reloads had a big affect.