How effective are angle of impact determinations for bullet holes in solid substrates?

Angle of impact determinations for bullet holes in solid substrates can be effective in estimating the trajectory of a bullet, but their accuracy is influenced by several factors, including the material properties of the substrate, the bullet's deformation upon impact, and any post-impact alterations to the hole. The shape and orientation of the hole can provide insights into the angle at which the bullet struck, though these measurements may require careful analysis and may not always yield definitive results. Additionally, environmental factors and the distance from which the shot was fired can complicate interpretations. Overall, while useful, such determinations should be corroborated with other evidence for more reliable conclusions.