when you have none, a repo is better thatn nothing imho. I improvised a coil spring, bought an original on ebay and now picked up one on Sarco...just to make sure I have one.
I have been trying to source a standard spring with no success. Numrich, Sarco, ebay...nada...so I researched torsion springs...sized the right one so I thought and ordered it...inserted it in the magazine and ... it works perfectly.