I have a 627 that an armorer installed a Wolff reduced power spring kit in. When I got it back it had very inconsistent primer strikes along with 1 un 10 fail to fires. He found some rub marks on the left of the hammer and installed some shims to fix it. No more rub marks, more consistent ignition but the primer strikes seem more inconsistent. I don't know how to post pics but some barely dimple at all. Any ideas of things I could try or do I just need to find a real gunsmith?

First check if your strain screw is screwed all the way in.
Easy to do, remove grips, screw is at bottom of front strap.
Let us know if that helps, plenty of ideas here.

Have the amorer put the original spring back in and not give it back to you until he test fires it and it works.

Make sure the strain screw hasn't been shortened, too. Some do that to try and lighten the stock spring. See if the end has been filed on.

Wolff states that light strikes and FTF are not uncommon with their reduced power springs.

Others have mentioned some fixes that do work. YOu did not say if the loads you are using are reloads or factory. Should they be reloads you can change primers that will help in eliminating ftf problems that sometimes come with a spring change. For example CCI primers are harder than Federal primers so a change from CCI to Federal will change a ftf lite strike problem on some firearms.

Just a thought.

I checked the strain screw. It was tight. I put the stock spring back in and now no fail to fires. I am using factory Speer and Remington ammo (tried both.)

Even though I'm not getting any failures now I've insppected the primers and noticed that there is still considerable variation in how deep the firing pin strike is. Some are very deep while others are a very shallow dimple. I don't understand why this is happening? I'm going to try to check headspace as soon as I get a chance. Has anyone else noticed differing primer strikes?