It's what they do...

Lie.

Dem Rep. Makes a Big Claim About AR-15 Rifle — and Conservative Journalist Offers $50K If He Can Prove It

Grayson makes an unsubstantiated claim. The journalist doesn't challenge him on the claim and it's out there across the airwaves and the internet for the world to here. It must be true 'cus it's on the News. The damage is done. We can prove it a lie over and over but the lies continues 'cuz the media doesn't care. The lie pushes their narrative.
Oh, and Grayson is scum anyway.