sighting Issues

[WDL71]

I have purchased a Smith 642. I am not a stranger to snub noses and have owned several different models, but this is my 1st air weight. I have noticed that no matter what ammo I use (125gr, 130gr, 158gr & different brands) bullet drop seems to be about 3-4 inches lower than where I am aiming and at different distances. I thought it might be my grip so I have tried more than one grip for stability and I am getting the same results. Any advice would be appreciated. I would like to fix this issue without simply adjusting the height I shoot at to off-set everything.

[Jack Ryan]

Aim higher

[Shadow9mm]

Are you covering the target with the front sight, or putting the top edge of the sight in the middle of the target. At what range are you shooting?

[tangolima]

Flinching perhaps? Did you try firing off a rest?

-TL

Sent from my SM-N960U using Tapatalk

[JohnKSa]

What sort of groups are you getting at 10 yards?

[Pumpkin]

Have you had a friend try it to see if the results are the same?

Is this with +P or std velocity, my 642 hits very close to POA with Rem 158+P SWCHP.

Also, a black Sharpie does help me see the sights better, if that’s a problem.

[Bob Wright]

As JohnKSA pointed out, what kind of groups are you getting? If you are getting good groups, you're doing nothing wrong. You need to file down the fron sight.

Rule of thumb: Move rear sight in direction you want to shift your groups. Move front sight in OPPOSITE DIRECTION to move groups to center. Works for fixed sights, just not as handyily done.

Bob Wright

[pete2]

No help but I have 2 642s, both shoot to point of aim for me. Shooting low, file the front sight to zero it. I have 2 pistols I have to file, maybe a couple revolvers. For some reason mfgs don't zero their guns. This includes Kimber, S&W, Ruger SA, Beretta, maybe all of them now. I think it's total lack of quality control now days.

[Super Sneaky Steve]

My 642 hits POI. Try adding a laser grip. You'll be able to tell if you're dipping the muzzle by dry firing with it activated and if you're not you can adjust the dot higher to compensate.

[Outpost75]

Have some body else shoot the revolver. That will reveal if it is grip, dropping the muzzle, etc.

In revolvers bullet weight influences point of impact more than velocity. Lighter bullets generally hit lower, heavier bullets higher.

In would first try factory wadcutters because they are an accurate load with mild recoil which is easy to shoot well. If you are unable to shoot TEN shots into 3" at ten yards off bags have somebody else shoot the gun.

If point of impact is off for windage the side of the front sight of a light alloy frame gun can be faced off in a milling machine on the side towards which you want the point of impact to be moved. It can also be done with a safe edged file if you are skillful. In the example shown a correction of 0.012" moves point of impact of a 2-inch snub 3 inches at 25 yards.

If point of impact is low firing the issued duty ammunition dress off the top of the front sight. If point of impact is high, a load having a lighter bullet is then required.

On steel framed guns the factory method to correct windage is to turn the barrel slightly by striking the barrel under lug with a babbitt bar. This is not done on alloy frames due to risk of frame damage.

Use the expression X=RE/D to determine the adjustment needed, where X is the correction, R is the sight radius, E is the impact error and D is the target distance. All measurements are in INCHES.

Refer to the photographs. A typical snub should be able to fire a 3-4" ten-shot group off sandbags at 25 yards with good ammunition. At least ten shots should be fired to accurately determine center of impact before attempting adjustment.

[Algunner]

Is the range well lit? The range I use is a bit dim and I have trouble focusing on the sights. No problem in a well lit room.