I put the reduced power springs in my Shadow 2, ran fine for about a year then the light primer strikes began. At first occasional and in the end it was like shooting a match 4 times. Put the extended length firing pin in, it did not help. I've gone back to stock.
I'm running reduced springs on my S2 with the extended pin. Did you also swap the firing pin return spring? If you did that as well it should light anything at 13lb main. Guys are running 8lb mains with extended pin and light spring but federal primers only at that point.
For the op as others have said I purchased my springs individually, no kits that I saw.



























