The MiniBooNE experiment has collected what is currently the world’s largest sample of vμ charged current single charged pion (CC1π+) interactions, roughly 46,000 events. The purity of the (CC1π+) sample is 87% making this the purest event sample observed in the MiniBooNE detector . The average energy of neutrinos producing (CC1π+) interactions in MiniBooNE is about 1 GeV, therefore the study of these events can provide insight into both resonant and coherent pion production processes. In this talk, we will discuss the long‐standing discrepancy in four‐momentum transfer observed between (CC1π+) data and existing predictions. Several attempts to address this problem will be presented. Specifically, the Rein‐Sehgal [3, 4] model has been extended to include muon mass terms for both resonant [5, 6] and coherent  production. Using calculations from , an updated form for the vector form factor  has also been adopted. The results of this improved description of (CC1π+) production will be compared to the high statistics MiniBooNE (CC1π+) data and several existing parametrisations of the axial vector form factor [8, 9, 11].