Fibre reinforcement of commodity polymers, such as polypropylene, is a well-established method for the manufacture of components with significantly increased mechanical performance compared to their unfilled counterparts. Glass fibre polymer composites incorporate short fibres (250 m) or long fibres (up to 30 mm in pellet form) within a polymer matrix. The resultant mechanical properties of any moulded component is highly dependent on the final fibre orientation, in the case of short fibres, alongside fibre length distribution and overall fibre dispersion for long fibres. In this paper we investigate the fibre orientation, length distribution and dispersion developed within a centre gated disc geometry both experimentally and, in the cases of fibre orientation and length, through numerical analysis within Autodesk Simulation Moldflow Insights. Primary goals of this investigation are: 1. to compare the differences and similarities between short and long fibre orientation developed within the disc region of the sample 2. to evaluate, in the long fibre reinforced case, the fibre length distribution at various locations within the moulding, including the sprue and nozzle sections 3. to evaluate, in the long fibre reinforced case, the fibre dispersion at various locations within the moulding, including the sprue and nozzle sections. Two different nozzle geometries have been tested, as fibre breakage and dispersion of longer fibres has been shown to be highly dependent on the early stages of the injection moulding process. Micro-CT has been used to visualise the fibre dispersion within the component, sprue and nozzles. Here the effect of decreased exit diameter in the nozzle section is clearly demonstrated, with aligned fibres appearing in the 6 mm case and a complex flow shown in the 3 mm.