A few I know of that won't censor firearms content:
Feel free to add any other open platforms...
LBRY - Content Freedom
Meet LBRY, a content sharing and publishing platform that is decentralized and owned by its users.
lbry.com
Full30
Watch 2A Gun Videos & Outdoor Sports Videos on Full30.com. Let your voice be heard without censorship or suppression.
full30.com
Feel free to add any other open platforms...