My Model 67 has been to Smith for combat action package. I have put very few rounds through it. I get light primer strikes on differing brands of ammo and on differing brands of primers in my reloads. Dirt and debris are not the problem. It varies both single and double action. Some will fire on second time around and some will not. Will in your opinion a new mainspring installed locally fix the problem? Really appreciate your expertise, thank you in advance, Harry.