EFFECTS OF RICOCHET ON THE MOTION OF PROJECTILES
Abstract
The cal .50 AP Bullet M2, the 20-mm AP Shot M75, and the 20-mm Shell Mark 1 with the nose of the Practice Projectile M99, both empty and filled with lead, were fired at depressions from 5 to 10 degrees so that they riocheted from the ground and passed thru two velocity screens or six yaw screens. The empty Shell has a density of about 1300 gr per cu in; the others, 2100. The AP Bullet and the empty Shell have a sectional density of about 3600 gr per sq in.; the AP Shot, 5200; and the lead-filled Shell, 6200. The experimental data indicate the following conclusions: The critical angle of impact is about 8 degrees for the cal .50 Bullet and 12 degrees for the 20-mm projectiles. The ratio of exit velocity to impact velocity depends on both the projectile and the angle of impact. The length of furrow, expressed in calibers, is largest with the AP shot, shortest with the empty Shell; it varies from 5 to 11 projectile lengths. The ratio of the angle of ricochet to the angle of impact rapidly decreases with increase in the angle of impact; it generally decreases with increase in sectional density. Some of the projectiles have a small deflection to the left, but most of them are deflected to the right. The magnitude of the mean yaw increases considerably with increase in sectional density, but does not seem to depend on the angle of impact; its orientation occurs in all quadrants, but most of the projectiles tend to point upward and to the left. An increase in sectional density increases the maximum yaw and decreases the minimum yaw.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 10, 1947
- Accession Number
- AD0479824
Entities
People
- H. P. Hitchcock
Organizations
- Ballistic Research Laboratory