Despite its advantages in terms of safety and cost, hybrid rocket propulsion has never attained mainstream adoption. A strong reason for that stems from the inherently low fuel regression rates, which have limited the applications and brought further technical problems when attempted to be solved by complex grain geometries or embedment of oxidizer into the fuel grain. Paraffin-based fuels were discovered to produce a combustion mechanism with mass transfer due to entrainment of liquid droplets of fuel into the gas stream, which is different to the combustion mechanism of traditionally used fuels, such as hydroxyl-terminated polybutadiene (HTPB), leading to higher regression rates. The use of such fuels as a solution to the problems with hybrid rockets is an active area of research. Swirl injection of oxidizer is another method identified to increase regression rate, and is particularly suitable for small scale motors. In this context, a paraffin-based fuel was formulated through a series of tests to evaluate additives to promote thermal radiation absorption, as well as evaluate the grain fabrication process. This fuel was then tested in a series of motor test firings. The performance of a lab-scale hybrid rocket motor using paraffin wax and gaseous oxygen (GOX) was investigated under a number of different conditions, including five different oxidizer injectors with varying levels of swirl. Pre-chamber length, fuel grain length, burn duration, oxidizer mass flow rate and fuel grain geometry were modified from a baseline and the influence in fuel regression rate and operating oscillations was evaluated. A new fuel formulation was developed with improvements over previous works and upwards of 40 test firings were conducted. Swirl injection increased regression rates to nearly 3 times that of the baseline axial injection configuration, while providing smoother operating conditions. The results indicate that, at least at these scales, thrust relative to size of a hybrid rocket can be increased simultaneously by the use of a liquefying fuel and swirl injection.