when limit screws don;t work what do i do?
 

Got to look at it up close - on my my Shimano sos - and the screws are just there in a space on the back wheel derailleur. They are no doing anything and as far as I can see are never going to. Obviously they did at one time but.....

Q: meaning the derailleur stroke does not stop where the limit screws end its inward or outboard travel?

If you damaged the rear derailleur? replace it..

Exactly. Consider it broken, especially if it's going to throw your chain into your spokes or frame.

incorrect cable tension can cause a false assumption to a faulty rear or front derp [added the ''p'' for funsake] .

and have the derailleur hanger alignment checked, at a bike shop, they have a special tool for that.

They are "limit" screws, meant to set the point where the derailleur stops at the top and bottom of the travel range. If the derailleur is shifted away from the ends of the cassette, the screws are not meant to be touching anything.

+1. Study the Park tutorial on derailleur adjustment, then come back if you still can't get it right. https://www.parktool.com/blog/repair...eur-adjustment