The house bill proposes that all ammo sold after a certain date must have a serial number on it. Then after a certain time period all ammo possessed must have a serial number on it. All ammo without serial numbers would have to be used or destroyed. Some individuals have 10's of thousands of rounds of ammo stockpiled. No serial number on your ammo would be a criminal offense. So reloaders would have to reuse spent casings with serial numbers or risk being charged for violating the law.
They also want to tax each box of encoded ammo. Like we don't pay enough in taxes.