Despite having destroyed and laid waste utterly to the bad gen from the English-language literature about Swiss 7.5x53.5 mm GP90 being semismokeless, The Bloke sets up a comparison, just because. Using original 7.5x53.5mm GP90 bullets in his 1889 Schmidt-Rubin, he loads 4 cartridges:

1x 32gn RS40, modern smokeless powder,
1x 31gn PC88 charge from an original GP90,
1x 30gn Swiss No.2 black powder to simulate semismokeless,
1x 65gn Swiss No.4 black powder.

The results are unsurprising. But the comparison is interesting all the same.