Janus you're ignoring that the weapon is Svartalalf tech and as such is some of the most advanced stuff we see in the movies. Asgardians, technological peers of the dark elves, make spears that shoot energy beams and a hammer that can, in the hands of Thor, create shockwaves, absorb high amounts of kinetic and electrical/heat energy, and survive rapid entry/renentry into earth's atmosphere. In fact, I was kind of surprised at how Thor was basically commanding his hammer to go into space to meet up with him. That's a durable little weapon.
Point being that Kurse has some good durability. The enchanted asgardian prison guard sword failed to penetrate his shouler, possibly getting stuck on his armor. He backhands Mjolnir, which in itself is considerable; Mjolnir is strong enough to cause shockwaves on impact, makes paste out of most foes, and split the Destroyer handily enough in the first film. The implication is that either the condition of being Kursed or the armor makes him more durable than Thor. And Thor/Loki already no sell bullets and can withstand thrashings from Hulk without death/paralysis.
Also Blax, your love for Hulk blinds you. I realize a half naked white man is too much for you sometimes, but you must restrain yourself.