SA Machine has been closed for almost ten years even though the website is still live. It’s unfortunate because they were a great asset for S&W 76 / MK760 owners.No experience with this company, I'm sure there are others who do have some though. They show the springs in stock. http://www.samachine.com/sw76.html
I have the springs and guide with rubber buffer. Hundreds of them,Are you talking about the semi auto, closed bolt SW760 made by Special Weapons?
They use a recoil spring on a guide rod assy. that also supports the smaller diameter striker spring .....
What is the diameter and length of your spring?
A "broken" recoil spring is not a common thing, and I'm not really sure how it would cause double feeding
Pics of bolt / spring/guide assy?
I have all the parts PM meI own an SW760 and it had a problem with double feeding. The gunsmith I took it to, said the recoil spring was broken. He can't find a new one. Q - does anyone know where I can find parts for this gun ?