My side business is being a FFL dealing in guns and suppressors. I started with square and then found out they are nut gun friendly and don't support any business that deals in the shooting industry. Square, goggle pay and a few others.
I ended up having to use TSYS Merchant solutions. Sadly they charge a 2.75% service fee that I have to pass on to the customer. Other then that, it allways works and there customer service is pretty good