So looks like the ATF is trying to reclassify 50 BMG uppers as actual firearms. https://www.thefirearmblog.com/blog...ying-50-cal-bolt-action-ar-uppers-as-firearm/ Will they do the same to uppers in .338 Lapua or .408 CT and 416 Barrett? Will they demand the upper receiver of all ARs be serialized? And if they do what about all the existing ARs that don't have serialized upper receivers? The only way to keep the insanity of the ATF in check is if we have a pro 2nd Amendment Congress and White House.