May 06, 2013
Up until 15 or 20 years ago, most 1911 front sights were staked to the slide. Staking worked OK for the tiny sliver of a blade John Browning originally envisioned or the old World War II-era pistol I carried in the Cold War, but you will see fewer and fewer pistols from today's factories with the front sights secured by swaging a bit of metal into a recess.
As higher profile sights became the norm in the '70s and '80s, the taller front blades put more weight above the attachment point and this increase in leverage, combined with the high round counts endured by competition guns, caused them to fly off occasionally. Military armorers building bullseye guns machined front sights from bar stock, cut a longitudinal slot in the slide and silver-soldered them in place. This was a secure setup. but changing the blade required a torch and refinishing the slide.
At some point a couple decades ago. dovetail front sights became available as custom parts. The downside of dovetail sights is the need for a milling machine to cut the dovetail. The upside is they require only one simple cut with the appropriate sized dovetail cutter. Virtually anyone with the most basic knowledge of machine tools can do the job.
The example I used for this article is a Novak front sight installed on a Springfield Armory, Inc. slide. First we measure the sight to determine the depth of the dovetail we will need. Measure the total height of the sight from the bottom of the dovetail to the top of the blade. In this case it is .259". Subtract the height of the blade itself (.185") for a dovetail depth of .074".
Using an edge finder, center your spindle on the front edge of the slide. Install a 65°x.330" carbide dovetail cutter. Move the center of the cutter back .320" from the slide face and touch off on the slide to find your depth zero. Then simply lower the cutter below zero .074" and cut straight across through the slide.
Pretty simple. One cut and it's over. Flooding the dovetail with cutting oil during the machining operation will increase the life of your expensive cutter. They can be resharpened, but they get a tiny bit smaller each time.
Also, keep in mind different brands of sights may require different sized cutters. For instance, we used a 65°x.330" tool (Brownell's 080-621-065) for this Novak, but we would need a 60°x.300" cutter if we were installing a Heinie front sight. Unfortunately, there is no industry standard.
After you have milled the dovetail into the slide, there will be some hand fitting so the sight is a press fit. A sight dovetail file of the appropriate angle, 60 or 65°, is handy during the fitting phase. The dovetail in the slide can be cold blued before final installation.
In the case of the Novak, there is a hole drilled vertically through the sight blade for a roll pin. The sight is left in place and a 1/16" drill is lowered through it and a hole is drilled through the slide. I usually wait until I have verified the zero of the pistol with the new sight(s) installed before I pin the front sight just in case I need to swap it for one of a different height.
Dovetail front sights are strong and easily changed if the need arises. What's not to like?
The carbide dovetail cutter enters the slide at 1200 rpm. Just take is straight across the width of the slide, and you're ready to install a new front sight.
Flooding the cutter with oil will help to increase tool life. The tool can be resharpened, but you lose a bit of size each time. So it's better to keep it cool and lubricated.
With a correct setup and plenty of lubrication, just one pass is all it takes to cur the dovetail for a new front sight. It will be much more secure than a swaged blade.
The slot where the original swaged front sight lived can be seen in the new dovetail. Swaging was fine for the original small front sight, but won't hold a taller one.
A 65 degree triangular file is used for final fitting. Only a few strokes will be required if your setup was correct and plenty of cutting oil was used. This can be a quick job.
New sight installed
The new sight installed. Note the hole in the blade for a roll pin. Norcross recommends checking zero before installing the pin in case windage needs adjusting.