It is a great cartridge, you are limited in pressures by the material and process technology of times.
The immature material technologies, process technologies of the era created an scandal when 1888 rifles blew up with service rifle ammunition. The Jewish owned company, Ludwig and Lowe
http://www.jewishencyclopedia.com/articles/10085-loewe-ludwig was a major manufacturer of 1888’s. The blow up of German service rifles created the conditions for the anti Semite Hermann Ahlwardt
http://www.jewishencyclopedia.com/articles/997-ahlwardt-hermann to publish “Judenflinten” in 1892 and claim the problems were because
the Loewes were members of an international Jewish conspiracy to secure control of the entire world; that the greatest obstacle to gratifying this ambition being the obstinacy of the Germans, the surest means of breaking that obstinacy was by the defeat of the Germans in war; that this could be most effectually secured by arming the German soldiers with defective weapons; and that to this end the Loewes had, by fraud and bribery, foisted upon the German military authorities nearly half a million guns that would explode in battle, maiming and disabling those who carried them and frightening their comrades, thus causing stampedes and routs. ,
http://www.jewishencyclopedia.com/articles/997-ahlwardt-hermann
Anyway, your rifle is of the same period, of the same technology, loading manuals keep the pressures down to 40,000 psia or so, and even though the design of the rifle could take 60,000 psia if made in today’s factories with today’s materials, it wasn’t. Accept the limitations, don’t hot load, the cartridge is perfectly fine with period pressures and velocities.