The STANAG 4496 Ed. 1 Fragment Impact, Munitions Test Procedure, specifies a standard test of 2530 +/- 90 m s(-1), an alternate test of 1830 +/- 60 m s(-1) and a standard fragment (projectile) geometry. The standard can be challenging to achieve and has several loosely defined and undefined characteristics that can affect the test item response. In particular fragment velocity variation, projectile tilt upon impact and aimpoint variation are commonly observed challenges. Achieving 2530 m s(-1) consistently and cost effectively can be challenging. Additionally, there are some efforts where over testing to higher velocities are viewed as desirable. The aimpoint of impact of the fragment is chosen with the objective of obtaining the most violent reaction: one test is conducted with impact in the center of the largest presented area of energetic material and a second in the most shock sensitive region. No tolerance for aimpoint is specified, although it is shown through high rate continuum modelling that aimpoint variation can be a dominant source for IM response variation. Continuum modelling also shows fragment tilt on impact is to be a possible source for response variation and it is common to observe fragment tilts of 30 degrees or even higher. The standard fragment is specified to be fabricated from mild, carbon steel with a Brinell Hardness (HB) less than 270. In the U.S., the fragment is often fabricated using ASTM1018 steel, which has a significant margin for mechanical properties that lay within the specification. These, as well as other gun testing issues, have significant implications to resulting IM response.