For the intended purpose this was just fine:

The Krummlauf was designed out of necessity. Ferdinand Porsche had produced 90 chassis for the Panzerkampfwagen VI "Tiger", which was not built in his factory but by Henschel. In order to be able to use the chassis after all, they were used for a new tank destroyer and were given the name "Ferdinand", later "Elefant" with improvements such as an MG-34 in the front. As the "Ferdinand" had no machine guns for close range, Soviet infantrymen on the Eastern Front were able to approach and fight the tank destroyers relatively safely. Thus, the curved barrel was developed for the Sturmgewehr 44 so that the tank crews could fire through the hatches of the tank and thus better fend off approaching infantry; there were also versions for inserting into the gun barrel.

Due to the bend in the barrel, the fired projectiles were subjected to strong friction and heated up so much that they finally burst as they exited. This meant that the charge effectively corresponded to a shot load, which was no disadvantage in close firefights. The wear on these barrels was high. In order to be able to aim around the corner, a groove was required in the crook barrel (from the height of the actual muzzle of a normal 44 assault rifle), in which a mirror device (prism attachment) was attached.

From the German Wikipedia article, translated using DeepL, 1 correction.