If I have new sights installed, how do they ensure the accuracy of installation? Bore sight or something such?
GN
I think the answer to your question is "it depends".
Are you buying target or duty sights?
Do you know what distance you want the sights to be "spot on"?
If your installer isn't local, I'd be sure to talk with them on the phone (not email) to make sure that they understand your requirements. If they know what they're doing, they should start by asking you several questions to determine your needs, before telling you what the solution is.
The good news is that the front sight on (I think all) new Glocks is simply held on with a small nut. It may take a special tool, but it's not fit into a dovetail, and installing a front sight takes about three minutes.
Buy
only a matched front/rear set of sights. Somebody should assure you that the two sights you're buying are known to work together
on your gun, and that they yield a given impact at a given range with a given type of ammunition. I think the default these days is that competition sights are set for center hold at 25 yards, but I have no idea where "defense" style sights are set.
If the installer isn't test firing the pistol with a known type of ammunition at a known distance to adjust them, then it's going to be up to you to make any final adjustments yourself. If that's the situation, then make sure that you get the installer to tell you what you need to do in order to make the rear left/right adjustments. Yes, it's as simple as tapping the sight one way or another, but
you need to know if the sights were locked in place with a set screw and Loctite. On some adjustable rear sights (Dawson, for example), there are hidden dovetail set screws that are only revealed by completely removing the elevation screw and folding the leaf up. If you don't do that, you can bang on the sight all day and it won't move until you've loosened those set screws.
If you are mailing the slide out to have the sights installed, I'd make sure the installer knows that you'll be making final adjustments, and that the set screw(s) and any Loctite should be LEFT OFF the rear sight. You can take care of those once you've made the final adjustments. What you really want the installer to do is to get the sights to fit the slide dovetail correctly (NOT too blasted tight!), without damaging anything in the process.
The installer fits the sight by carefully filing or sanding the base and "angles" of the sight dovetail, which gives it enough clearance to fit the slide dovetail snugly. All sights that I know of come with a set screw to hold them in place, so with a little Loctite this is a good arrangement, and will enable you to remove the sights later if you change your mind about them. I don't think that rear sights should fit the dovetail so tightly that the sight pusher tool groans and creaks as it wedges the sight into the dovetail. I know about those sounds through experience.
If you are not buying special target or duty sights, I recommend the polymer fixed Glock rear sights, with a polymer Glock front sight. I have a bunch of these and have found them to be inexpensive and of good quality. They come in four different heights (6.1mm, 6.5mm, 6.9mm, and 7.3mm). The height of the sight is marked on the side, and the best way to explain this in writing is as follows:
(for purposes of this explanation, this is a dash _ and this is a hyphen -. The hyphen is shorter.)
6.1mm has a dash with a hyphen beneath it (on the right side of the sight).
6.5mm has a dash.
(according to the Armorer's Manual, this is what was installed at the factory on your G22)
6.9mm has a dash with a hyphen above it.
7.3mm has a dash with two hyphens above it.
Look at your pistol to determine which one you have, and you can decide if you need one of these alternatives. For example, if you have a 6.5mm and you're shooting high, you want a lower rear sight, so get the 6.1mm. According to the Armorer's Manual, "
A one-step change in rear sight height represents aprox. (sic) 2.4 in. (~61mm) difference in bullet impact at 27 yards (25 m) for GLOCK 17." They also add that "
Rear sight height may vary due to factory test-firing."
Or, you can get the Glock polymer adjustable sight, which is inexpensive and of good quality.
The best part is that these Glock sights can be removed or installed by somebody with average skills, dexterity, and a light punch, because they are held in place with a piece of spring steel that fits under the polymer sight body. They really can be tapped in and out, and don't have to be
DRIVEN in and out with huge force.
Glock also has night sights, but I have no experience with them, so I can't comment on them.
Once you do have the sights installed, I think it's a good idea to make up some special targets and fire on them from different, known yardages. For this purpose, I use the white side of IPSC targets, with a plain black cross painted on them. The cross in centered on the target and has arms that extend out 6" from the center, and about 2.5" thick. At 25 yards, this is a pretty clear target. You can sight on it with a center hold (the front sight right over the center of the cross..I use fiber optic fronts, so I put the "dot" right on the middle of the cross), and fire away. With a group of five or six shots you'll have a good idea of where your sights are set, and then you can change the yardage. You should know how the gun shoots at, say, 7, 11, and 25 yards. Those are three that I use because they're commonly used in USPSA stages, with 25 being the longest I think I've seen (so far). Take it slow, concentrate on your trigger work, and you'll get some useful data to store away for future use.
This ended up being a much longer response than I planned when I started, so please forgive me if I rambled.
Chris