My 520 was purchased several years ago and now one of the springs is turning in it's location. I'll be sending it in for warranty repair. My question is, "Are the springs that come in the 520s any stronger today than several years ago and is there a BM upgrade spring kit available?"

they'll be stronger since they won't have been stressed as much. Omega spring replacement is something BM does, pretty sure they won't send you springs.

Thanks for your reply Skimo. I read from your other posts that they wouldn't send out springs and I don't have any intention on doing it myself. I was wondering if there had been an upgrade or increase in the spring tension from the earlier models.

not that I'm aware of, no.

Sorry, I don't have that kind of info, maybe try calling BM and asking about them.