I have used .080, .100, and .120 inch material and tend to not want to use anything thinner than .100 inch thickness. The .080 material felt springy when handled, and I have stayed with the two thicker options since then. A concaved cross section running across the inside trigger bow will make it more rigid, but still leaves it too springy across the rail and back final. The .120 feels better but requires a bit more work to make and clean up to the final profile/finish.
Roger Sells