YUMA PROVING GROUND, Ariz.-- Whenever the United States military fires an artillery round, the reliability of that round was meticulously proven at U.S. Army Yuma Proving Ground (YPG) long before making it into the hands of Soldiers.Lot acceptance testing, the testing of a sample of fielded but newly produced munitions in real-world conditions to ensure reliability and effectiveness, is another important part of YPG’s munitions and weapons mission.Every component of a shell, from the round and casing to the primer and propellant, are tested at YPG. The velocity of the fired round is measured, as is the dispersion of the shell when it hits its target. Testers also look for residue in the gun tube, using a camera aimed at the breech during the test and physically inspecting it after the round has been fired.Accurately measuring this data on rounds that travel about one mile per second requires the assistance of some of the world’s most sophisticated high-speed cameras and triggering equipment. YPG’s scientific photographers have cameras capable of shooting 100,000 frames per second, though for this particular test they use only a small fraction of this impressive capability. As each round is in flight, workers back at the howitzer take readings from pressure gauges inside the gun barrel.Lot acceptance testing comprises a large ratio of the post’s Munitions and Weapons workload, but every such test is unique. Some even combine facets of developmental testing as rounds are upgraded. One recent case in point involved a test of the M795 High Explosive 155mm projectile that looked specifically at the munition’s metal parts, which has a different process than other lot acceptance tests.“We are looking for any metal parts separation or obturation,” said Daniel Lopez, test officer. “We’re also getting downrange observer data. We’ve changed some of the locations of our cameras to obtain higher quality footage of the muzzle exit.”“Normally we wouldn’t do the metal parts test here,” added Kermit Okamura, Munitions and Weapons Division Chief. “They sent samples from the production facility because they didn’t want to slow down production. We were able to piggyback on to our other test because the support elements are similar.”For decades, YPG has been at the forefront of artillery test and evaluation. This fact, combined with the proving ground’s extensive institutional knowledge makes it an ideal test location for all facets of artillery development and sustainment.“If this metal parts test achieves the results they want, they can start building that blend,” said Okamura. “What we’re testing today will eventually come back for lot acceptance testing of the full-up rounds.”