This paper examines the dynamic pressure effects of a long-duration blast load on small-diameter circular and angular structural steel members for a Mach stem region where a shock wave travels at near the speed of sound. In complicated flow fields, where fully coupled analyses are not reasonably practicable, the correct application of translational drag loads is vital. The variability in drag coefficient for members of the same shape can differ greatly, owing to stagnation of the flow and the level of flow field obstruction. To investigate this effect, this paper details a simplified experimental trial conducted in the world's most powerful blast tunnel, the US large-blast thermal simulator at White Sands Missile Range, New Mexico. Four assemblies were examined based upon hollow steel sections mounted at different angles and positions. The experiment indicated a drop in drag coefficient for shielded circular members in close proximity of approximately 40%. The drag force on unshielded sections was lower in magnitude than initially expected; this was attributed to an absence of flow stagnation and reduced boundary layer effects. Comparative square and angled sections displayed approximately 50% higher values than circular members.