The Austrian Lorenz rifle had a characteristic tendency to curve and overshoot the target. The French learned they could exploit this by ducking and closing in quickly, so Prussia could adopt bayonet tactics during the Seven Weeks War to exploit them as well.
Or conversely Prussia might put more emphasis on their artillery arm instead. Could have interesting effects later on. Historically Prussia focused on modernizing their infantry before their artillery. So during the Austro-Prussian War, the Prussians had superior infantry but inferior cavalry and artillery arms. Once they modernized their artillery the dynamic was reversed during the Franco-Prussian War. With Prussia now having inferior infantry with outdated rifles, but vastly superior artillery and howitzers to the French.
In this tl when they purchased new artillery in the 1850s (presumably of muzzle-loaded brass) and new rifles in the 1860s, we might instead see both sides enter the Franco-Prussian War with modern Chassepot-Mauser rifles but Prussia without the Krupp Steel.