I think politics because of his reasoning: Getting the online site because of how much big tech and credit card companies have been trying to stifle online gun sales.
I just saw this on Mornings With Maria. I'd not heard of Grabagun, but it appears to be similar to other "online big box" companies. He invested in partnership with Omeed Malik. It will be trading on the NYSE.
The company:
https://grabagun.com/