How to Mount Scope Rails on a 1911 for Bullseye Competition

How to Mount Scope Rails on a 1911 for Bullseye Competition

NRA Conventional Pistol or bullseye pistol competition was always about shooting iron-sighted pistols and revolvers until a couple decades ago when the NRA changed the rules to allow non-magnified optics. Suddenly, everyone was running red dots on their .22 and centerfire target pistols.


The advantage of a red dot over iron sights for older people like myself with poor eyesight is that we are no longer required to focus on the front sight to shoot good groups. Shooters who would have retired from competition in their '50s are shooting into their '70s. Eyesight is no longer an issue.


Mounting a scope rail to the 1911 slide isn't difficult, but you have to pay careful attention to locating the screw holes. I use the rail from Clark Custom Guns. Machined from aluminum, it is attached with four 6-40 socket head cap screws and provides a clean, low profile installation.

We begin our installation by removing the iron sights from the Springfield Armory slide.  We also want to remove the firing pin and firing pin spring, since we'll be drilling into the firing pin tunnel. Clamp the slide in the mill vise and level it. The rail has a taper, so I set the rail on the slide and level it with a machinist's level.


With an edge finder, we center our spindle directly over the muzzle end of the slide and zero our X and Y axis. Clark does not provide a drawing of the rail showing the distance center to center between the four screw holes so we'll have to measure it.

Attaching a pair of centerline gauges to our digital caliper, we take the necessary measurements. The first hole is .980 inches from the muzzle, so we move our mill table over that distance and spot the hole with a center drill.

Spotting the hole is important, since we are drilling on a curved surface and we don't want the drill to walk off the center line. After spotting the hole, we change to a #33 drill and run it straight down through the slide. Then we install a tap guide in the chuck and tap the hole by hand for 6-40 threads.

Drilling and tapping before we move the table insures everything is in perfect alignment. Now we move the table over 1.775 inches for the second hole and repeat the same procedure. The third hole is 2.350 inches from the second one and deeper. We drill down through the thick part of the slide into the firing pin tunnel and stop.

The fourth and last hole is .900 inches behind the third one. After all four holes are drilled and tapped, check the firing pin tunnel for burrs and clean it up with a chainsaw file as necessary. We don't want burrs inside the tunnel interfering with the firing pin.

Test fit the rail. If everything looks good degrease the tapped holes and the top of the slide. I use Shooter's Choice Quick Scrub III as a general degreaser. The screws should also be degreased, and I keep a glass jar of lacquer thinner on the bench for this purpose. Drop them in the jar and fish them out with a magnet a few minutes later completely degreased.

Now we apply a few drops of Loctite 620 retaining compound to the top of the slide as extra insurance it won't come loose and screw down the rail with the four screws which are each treated with a drop of Loctite 262 threadlocker.

With everything tightened down we let the adhesives set up and mount our Ultradot red dot sight, confident our mounting system is secure. Keep in mind a slide-mounted rail is intended for light target loads (semi-wadcutters), not factory hardball. If you are running full power loads with a scope, a frame mount would be recommended. Also remember you have increased slide mass quite a bit by adding a scope so a reduced power recoil spring will be needed for proper function with light loads.

Popular Videos

Ruger introduces Rifles Chambered in the All-New .350 Legend

Two Ruger American Ranch rifles and the AR-556 MPR are now chambered for Winchester's .350 Legend cartridge.

New addition to the Browning X-Bolt rifle series

New for 2019 is the Max Long Range model featuring a composite Max stock with fully adjustable comb, spacers for adjusting length of pull, stainless fluted heavy sporter barrel, threaded muzzle brake and extended bolt handle.

New Bushnell Prime 1700 and Nitro 1800 Rangefinders

Jake Edson of Bushnell Optics tells OSG's Lynn Burkhead about the brand new Prime 1700 and Nitro 1800 rangefinders.

See more Popular Videos

More Handguns

Handguns

S&W Introduces Performance Center 380 Shield EZ Pistol

Jim Grant - April 23, 2019

Smith and Wesson just announced the latest addition to their product lineup: the 380 Shield EZ...

Handguns

Mauser's M1930 'Broomhandle'

David M. Fortier - March 13, 2019

The Mauser M1930 'Broomhandle' may not be practical, but they're cooler than Steve McQueen.

Handguns

The Shadow Systems SS9F Custom Glock

James Tarr - April 03, 2019

Shadow Systems' SS9F is the Glock 17 platform tricked out in a fully configurable custom...

See More Handguns

GET THE MAGAZINE Subscribe & Save

Temporary Price Reduction.

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW OUR CURRENT ISSUE

GET THE NEWSLETTER Join the List and Never Miss a Thing.

×