March 20, 2013
Sometimes an armorer may find it necessary to remove the front sight housing on an AR-15/M16 type rifle. Standard front sights are pinned to the barrel. Manufacturers such as Rock River and DPMS use straight pins, while others like Colt and Bushmaster employ tapered pins.
Moving these pins requires a strike from a hammer and punch, and the front sight must be solidly supported to prevent it from walking around on the bench. If the sight is allowed to move, you may end up with unprofessional looking dings in the steel around the pins where the punch slipped.
Brownells produces a special polyethylene bench block designed to aid both removal and installation. The block is machined to accommodate most front sights, although I have seen a couple that were too big to fit the recess.
Taper pins must be driven out from the small end (left to right). The ends of the pins are rounded and a standard punch will tend to slip each time it is struck. Use a Brownells Taper Pin Starter Punch if possible.
The end of this tool has a concave face designed to fit the ends of the pins. This is only a starter punch. Once the pin begins to move, a standard 1/8-inch punch may be used to drive it out. Before reinstalling the front sight, a size 2/0 taper pin reamer may be used to clean up the holes if they are burred.
Another pin removal tool comes to us from X-Ring Products. This tool consists of a clamp that fits over the front sight and provides a guide that keeps the punch from wandering. Machined from 6061 aluminum and hard anodized, this kit comes complete with a short starter punch and a standard length punch. I have found this device effective for punching out tight taper pins.
Front Sight Block
Norcross' well-used Brownells front sight block has seen many a pin driven out and replaced. This part is essential if you plan to work on many ARs.
Front Sight Positioned
A front sight positioned for removal on the Brownells block. Combining the block with a taper pin starter punch will keep you from marring the sight.
X-Ring Precision Tool
The X-Ring Precision sight pin removal tool comes packed in a small Pelican case with punch and Allen wrench. It's great for the tightest pins.
Rear Guide Hole
Here the rear guide hole of the X-Ring fixture is positioned for removal of the rear pin. With the tool clamped in place, the punch can't wander off course.
Tightening the X-Ring
The X-Ring fixture is tightened in place with a socket head cap screw. The thumbscrew adjusts a plastic bumper that bears against the sight so the fixture won't rotate.