I was doing some research the other day and stumbled across www.buffaloarms.com They carry all sorts of obsolete ammo for things all the way back to the early post Civil War years. They are not cheap but before you give up on an old piece because the ammo is obsolete give them a shot. They have .43 Spanish and it has been rare for years... and costly! They have new stuff with black powder for around $3 each.

The only reason I post this is to help out fellow shooters.

Dave Gullo is one of the good guys. I've never ordered ammunition from them, but have ordered bullets and cartridge cases for some oddballs. Good service, fast shipping. Getting hold of them by telephone can be a challange, though.

I have ordered from buffalo and been pleased, Got brass for 8X50, moulds and sizing die. well worth the money even though it was a bit expensive. Order was shipped promptly. He even sent me a couple of sized brass free to check before I bought the brass The old M95 Budapest shoots high, but the ammo worked well in it.
Sailr