Moderator hso said "smokeless powder".
Isn't that what the "Dutch" farmers successfully used in their Mausers against the British in the Boer Wars (Suid-Afrika / South Africa) ?
Unrelated sidenote: young Winston Churchill escaped Boer captivity and somehow traveled alone for a few days to reach British lines.
To contradict my comment on a previous page, it might have been the rifled bore, allowing much better rifle accuracy and range?
Iirc the rifled bore was used by some Union forces in the US Civil War. It also seems to have worked well in whichever cannons.