This came up several years ago. The action taken was to leave the approval at the discretion of the local range. After all, it is their targets. To my knowledge, none of our present Posses have indicated that they do not allow the Spencer with 56-50 loadings. After all, the foot pounds are the same as a 45 LC with 255 gr. factory loads. At our ( JCR ) range, we have had no problems with their use.