You have to smooth out the edges so it doesn't eat the retainer either way with lots of spring pressure. That is also with less expensive springs. Check this out:
http://www.iskycams.com/springs.htmlTake note of #4 and #5. If these springs don't work I'll move up to Isky 1699 which is the same spring (all specs) in Marathon-RAD material. They are $100 more than the 9999-RAD's so I'm hoping these will work for a while.
Also of note here:
http://www.cvproducts.com/Products.aspx?MFGID=PSIManley sells what I think is a Goodson tool as well:
