Shockwaves are a powerful tool for studying materials at extreme temperatures and pressures. The method used to generate the shockwave influences the pressure, area, and duration of the shock pulse. Some of the highest-precision, high-pressure equation-of-state measurements have been obtained using electromagnetic flyer acceleration. However, the efficiency of converting electrostatic energy to kinetic energy in this technique is limited (a few percent). In contrast, the electric gun, an alternative electromagnetic flyer launcher pioneered in the 1970s that utilizes the explosion of a metal foil to drive a dielectric flyer, has demonstrated efficiencies of up to 25%. Despite this, the technique has been largely neglected in recent decades due to challenges in launching flyers thicker than 0.25 mm, which limits the shock pulse duration on impact and, consequently, the launcher’s applications. In this work, advances in magnetohydrodynamic (MHD) modelling were employed to redesign the electric gun. Simulations using a novel 0D model and a 2D MHD hydrocode with material strength were used to investigate the behaviour of the foil explosion and flyer deformation. Experiments using a numerically designed load were then conducted on M3, a 2 µs rise-time, 1.2 MJ pulsed-power device. The numerical investigations and experimental are presented, demonstrating the acceleration of polyimide flyers up to 2.0 mm thick to velocities exceeding 10 km/s, generating pressures of up to 80 GPa in PMMA targets, with efficiencies of approximately 10% and stand-off distances of up to 10 cm. These findings highlight both the improved flexibility of the electric gun and the technique's significant potential as a tool for high-energy-density science.