Credit card for guns, accessories, ammo, and everything else I might buy. Food also.
I get points that are redeemable for nights at a hotel. What's not to like about not having to pay for lodging when I go on vacation?
I pay it off every month.
The "paper trail" doesn't bother me. I intend to spend my efforts protecting our gun rights, instead of hoping Big Brother doesn't find my bought-for-cash-at-a-gun-show rifle.