The analytical model developed by Gurney is a seminal tool for analyzing the acceleration of metal flyers driven by detonating high explosives. Despite the continued relevance of this model, relatively few experimental validations over a wide range of flyer-to-charge mass ratios exist in the open literature. The current study presents experimental results for planar aluminum flyers propelled by a conventional explosive over a range of mass ratios varying from 4.65 to 0.03. Flyer velocity was measured via Heterodyne Laser Velocimetry (PDV), permitting a continuous measurement of the acceleration process. Measured flyer velocities are compared to terminal velocity estimations from the Gurney model. Experimental terminal velocities are compared to the open face and asymmetric sandwich Gurney models. Excellent agreement is observed for terminal velocity predictions considering the gasdynamic simplifications inherent in the model formulation.