Actually, this sounds like an excellent idea to catch those criminals who have left a bullet in their victim or victims. Surely this is a small price to pay to catch criminals who are involved in what could be the murder of some innocent victim.
Over time when the system of registration becomes effective there will be traceability of the ammunition to the source of production and then a paper or electronic trail to the perpetrator or legitimate owner of the ammunition. If the ammunition is either stolen or obtained through nefarious methods then this will at least give the police authourities a starting point to provide further information in an investigation.
With so many folks dying from gun shot wounding this can only be a good idea. It is a small price to pay surely if it saves the lives of even just an handful of Innocent victims and puts away the perpetrators. It will of course take many years to start working until the old ammunition held is exhausted. There are of course work arounds if the system or ammunition registration is implemented, but then again your average perpetrator probably isn't the sharpest tool in the box. Just remember to collect all your cartridges at the range so as to insure your not framed for 1st degree murder though.