Dovetail Front Sights for the Colt 1911s
Colt has used at least three different non-interchangeable dovetail front sights in the course of their production; the Novak, the Heinie and the C-More. You will need to compare your slide to those shown to determine which dovetail configuration that you have.
These dovetails differ in three main aspects - the distance from the front of the slide measured to the centerline of the dovetail, the depth of the dovetail and the front to back width of the dovetail.
The Novak dovetail centerline is typically cut about .330 to .365" from the front of the slide and the sight dovetail is .075" deep and .330" wide -w- 65° angle.
The Heinie dovetail centerline is typically cut about .250" from the front of the slide and the sight dovetail is .060" deep and .300" wide -w- 60° angle.
The C-More dovetail centerline is typically cut about .275" from the front of the slide and the dovetail is .070" deep and .335 wide -w- 65° angle.
There are pictures comparing the C-More and Novak dovetails in the C-More section.