I have been using a product called ShapeLock for some time now. It is a malleable, plastic based construction material that has infinite uses.
It comes in a bag of round, white beads. The beads are placed in hot water for a short amount of time until they become translucent. Once translucent, the Shape Lock becomes similar to a clear putty. I find it incredibly easy to make jigs for various firearm components out of this material.
Shape Lock in clear putty form. Mold to shape with your hands.
One example I can think of that I have used over and over again is a front sight base jig. Brownells sells a FSB jig, but if you read the reviews many people comment how it doesn’t work when they have free float rail X, Y, or Z installed. Solution? Shape Lock.
Press the component into the shape lock and either leave it in place or remove it. Let the shape lock cool down.
If you are unhappy with the outcome of the mold, the shape can be recycled into a new shape simply by placing it in hot water again. This lets you recycle the shape lock for years.
The completed jig will be a perfect fit for your project and if you are wrenching on your AR at home, this product will help tremendously. I have used it for a jig to hold the rear sight assembly while I install the windage roll pin as well as well as numerous other small projects.
The completed FSB jig
Shapelock can be used to make a variety of jigs: here I used it to hold a A2 rear sight to allow easier installation of the windage dial roll pin.
