I just got some Trijicon HD night sights. I am installing them on my Sig 229.

I am using a MGW sight pusher. What is the easiest way to make sure my sights are centered? I have some calipers. But when you index off the rounded corner of the slide, it's iffy.

I know the sight pusher does have the marks, but has some play either way, so you can't use that to line them up.

Anyone have any advice? How do you guys do it?

FWIW, I just eyeball them. It's pretty easy to see whether there is equal distance in the dovetails from the side of the sight bases. Make sure you use good lighting.

I use hammer/punch method and am usually very close to POA/POI. With hammer/punch you need a vise of course. If necessary, I bring the gun home and only a slight tap on the appropriate side will correct it. With your sight pusher, you can do it at the range.

Note that it is possible for even a perfectly centered (mechanically) set of sights to show a slight variation from POA at the range. In addition, variations in shooter technique can cause the same issue.

That's pretty much what I did. But used the sight pusher. Then I tried to check with calipers.

The problem is that a supremely precise centering doesn't necessarily transfer to a somewhat imprecise human at the range.

Most of my shooting is fast draw/fire drills at 15 yards and under. Small variations in mechanical precision and my own technique generally don't really matter.

Take a handgun that shoots precisely POA/POI at 25-50 yards and give it to three other shooters. Odds are POA/POI will vary somewhat due to individual shooter technique.

All that matters is that the gun shoots where YOU want it to at the desired distance(s). First thing to do, of course, is make sure the issue isn't your own technique.

I was playing with a new back strap on my Gen4 G19 last week. Subjectively, felt very good in the hand. Took it to the range and had very good groups from the holster, as usual. But they were about 2" to the left of center POA/POI. Took a deep breathe and fired two slow shots at 7 yards. They were perfectly centered and touching.

The larger grip was causing a slight misalignment to the left when shooting at speed. I removed the back strap and went back to the naked frame. Everything OK again. Another case where good/bad subjective feel doesn't translate to the expected result during live fire. I have guns that don't feel good in the hand (subjectively) but shoot extremely well. Have some that are the opposite. Paper never lies.

Use a flat bar of some type, I use a small machinist square, but whatever size is convenient. Place the flat bar on the side of the slide so that part of the bar overlaps the sight. Use your calipers to measure the distance from the sight blade or notch to the bar surface. Repeat on opposite side. This way you are registering off the slide sides and the sight itself. Easy and repeatable.

Thanks I'll give it a try

quote:

Originally posted by Nipper:
FWIW, I just eyeball them.

This is how I do them. Get the light to shine on the sight so both sides are illuminated and you should be able to pick out if it is off centered. As another check, I use a metric rule calibrated in mm (cannot read the .5mm side ). Measure each side from the sight base to the edge of the sight "slot". Again, you should be able to see very closely if one is off more than the other.
 
After a range visit, I always use the visual method the ensure they have not drifted.