Have a rifle that is not completely responding to bedding. Think I ought to try putting a pressure pad under the barrel at the end of the forearm.

Is a synthetic stock ... what's the right way to make such a pad?

Thanks!

I just use a piece dense cardboard epoxied in the barrel channel. You will, of course, want to experiment with the thickness as it will determine the upward pressure.

You can always use shim stock to temporarily add a pressure point at the end of the forend. If you clamp the stock in a holding fixture so that the forend is free, you can use most anything that holds a measured weight hung underneath by the swivel stud, and then use the appropriate thickness of shim stock to fill the gap. You may start off with zero weight and shim the stock so that it is neutral. Then shoot groups on paper to see if it responds. If not, add some weight. Some use nothing more than a milk jug filled with water. Use a scale to measure the weight in pounds starting off with something light. If you use plastic shim stock, you then stack the cut pieces of shim to fill the gap. You might make adjustments in 1/2 pound increments and then test for groups. IIRC, most pressure pads are somewhere in the range of neutral to a few pounds.

Once you find the sweet spot, you duplicate the weight on the forend with the stock clamped in the fixture while you pour the pad with epoxy. The epoxy will then fill the gap same as the shim stock and it will then be permanent. Hitting the right spot on some factory barrels can turn a poor shooter into a very good shooter.

Good Luck!

You want to use something that is not going to absorb moisture and swell, changing your POI or causing rust. Brass, PVC, plastic, and epoxy are all good materials. I use cardboard to test different thicknesses and to see if the rifle likes that pressure point.