For anyone interested, I just got a flyer from Century Arms (www.centuryarms.com) and they are showing to have some .577/.450 Kynoch ammo (480 gr) smokeless load, 10 round packs for $29.87. Now you know what I know, in case someone is looking.

That is a great price if you compare to other out there.
I bought a bunch for my Martini and enjoyed a couple of boxes.
It was very much similar to shooting my flintlock with a delayed detonation.
Frank