I just aqquired my first Double rifle it is a H Scherping of Hanover Germany made around 1892, this rifle has beutiful damascus bbls, hammers, flip up leaf sight as well as recessed tang sight, henry style rifleing, horn butt plate, set triggers, fine rose & scroll engraving, case colour action and backlocks & chambered in 500BPE 3". This maker was incredibly skilled as evidenced in the other Scherping guns I have. This is my first exposure to big bore cartridges, where do I start, I am a reloader and will end up down that road but first I need to get my hands on some cartridges and or reloading components. This gun is black powder proofed so should I start by buying some loaded black powder cartridges or start by reloading and using smokeless for black? Where can I find ammo or components (Dies, load data, brass, bullets), all information greatly appreciated.