I have a 586 thats having light primer strikes. I have already installed a new spring kit from Midway USA, still have same problem. Two things I have noticed, the firing pin appears shorter than all my other Smith's, and I have more than twenty, model 66's,19's,686's,36's,65's,10's, etc,etc. Also when the revolver does shoot ok, I average two light strikes per six shots, the impression left on the primer appears to be off to one side. All my other Smith's have primer strikes dead center.
I bought this gun used and I am wondering if someone didn't change out the firing pin and put the wrong one back in, but I'm not sure. Any suggestions before I change out the firing pin would be greatly appreciated.

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install a OME mainspring, a mainspring tension screw, and a trigger return spring.
This should cure your Model 28 issue. If not install a OME firing pin.

You don't mention if you are having this same problem both in double action and single action, or the dash number of your 586. It appears from the photos that the cylinder may not be "carrying up" completely, that is, the cylinder may not be locking before the hammer falls. If this is the case, there could be an issue with the hand, cylinder stop, damage to the stop slots in the cylinder or the cylinder assembly/yoke being out of alignment. (or, perhaps, being impacted with shooting debris) If modifications have been made to the internals, then over-rotation of the cylinder could also be an issue. You can check to confirm cylinder alignment or mis-alignment by using a range rod.

First of all, make sure the mainspring strain screw is tight, and that it has not been shortened.

It's possible, but unlikely that someone has changed the hammer nose. If you can, check to see how far the nose is protruding through the bushing in the breechface. Protrusion should be apprx .045" - .050"....or about the thickness of a dime. You can check this by opening the cylinder, and while holding the thumbpiece back cycle the trigger and hold it fully back, and with the hammer fully down, check the pin's protrusion.

Other more likely issues would include a modification (shortening) of the mainspring strain screw, and or end shake on the cylinder. After a thorough cleaning, use a feeler gauge and measure the "rear gauge" or headspace. The headspace between the breechface and rear of the cylinder should be .060" - .068"...... too much headspace, or end shake on the cylinder, can cause carry up issues, and light strikes. These things come to mind, but there are many, many more possible causes for your light strike problem. Trying to diagnose such problems without being able to examine the gun is like trying to do surgery over the phone. Sorry I can't be of more help.

If you are unable to determine with certainty what the problem is, perhaps a visit to your local trusted gunsmith for an evaluation would be in order. Or, if you don't have a qualified gunsmith nearby, S&W is still an option for diagnosis and repair. If it's a "no dash" and hasn't had the recall work done, you could have that done while the gun is there for repair of these current issues.

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Ret. LE, FA Instr, S&W Armorer