Given that at $0.05/round you're going to sell approximately zero rounds, though you might sell a fair number of guns even with a $25 tax on them (lower than many FFL transfer fees!), I wonder how long it would take to make up for the legal fees expected from fighting the NRA and company over this?
I mean, I wouldn't be surprised if they quickly end up 40k guns into the hole, meaning it would have been cheaper to just fund the places directly.