Decided to slick up my Model 69 this morning and add a Wolff Reduced Power Mainspring and a 14 lb trigger return spring. Also polished the sides of the hammer and the rebound spring slide. Put the weapon back together and tightened the mainspring strain screw to the max. Action very smooth but very light? Suspicious from the getgo!

Went to the outdoor range with a Chronograph session in mind! First five rounds fired without fault. Next cylinder full was 4 out of 5. Next cylinderful was a Hornady factory load and it was 4 out of 5 double action. Back to my reloads 3 out of 5 single action! Enough frustration!

Went home and replaced the Wolff spring with the original mainspring. Back to range: 5 out of 5 single action, but 4 out of 5 double action.

Gun was 100% reliable before! How do I get this gun back to 100% primer ignition? This is my woods gun! Action is a lot smoother but the hammer doesn't have the mass to ignite a hard primer!

Same strain screw in both cases?

With the factory mainspring back in it should be fine but obviously something changed. How does the factory spring look? Did the mainspring get bent? You could put a fired primer (minus the anvil) between the strain screw & the spring to give it a little more pressure on the mainspring, just to see if it changes.

How's the firing pin look? Did you remove it when you did the work? It's OAL" should be > .490" long.

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Waiting for the break of day

This is a classic... the factory strain screw is too short when used with the rib on the Wolff spring. You need to use a longer screw to compensate for the rib recess the end of the screw fit in.

On the 986 L-frame that comes with the lighter Performance Center mainspring, which looks suspiciously like a Wolff reduced power spring, rib and all, S&W uses the longer strain screw for a square butt frame on the round butt frame.

Also... through my own experiences with installing a Wolff reduced power mainspring in my M625-8 and M69, and reading other posts on the topic... installing an APEX tactical XP firing pin kit (https://store.apextactical.com/WebDi...Details/192059) when a reduced power mainspring is installed, effectively addresses light strikes. I also installed a kit in my 986 that came with the lighter mainspring.

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Conrad
SWCA #1830 SWHF #222

I'll bet somebody ground the strain screw short at some point. Cranking it into a Wolf ribbed mainspring can actually shorten it more because it tapers the tip. You probably need a strain screw. I would also make sure the firing pin is proper length (.495") and not one of the midget pins SW loosed on the world.


You said:

"Action very smooth but very light? "

It's been my experience that for proper strike force, the DA pull with a Wolf RP spring should be about 8.5 - 9# ballpark. If it is SIGNIFICANTLY LESS, that means the strain screw has been shortened and will cause light strikes using the RP spring (and maybe even a stock spring). That's why I hate it when people grind the ends off strain screws, can't tell by looking. Drives you nuts.