929 PC - light strike, mark, no bang

Mr_Garth

Mr_Garth

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My spiffing new 929 has developed on issue :(
So far I've shot some 500 factory rounds thru it without hickups. Today it started to rain in my nice SW paradise. I'm getting misfires, say every 3rd or so.
I'm running DAA .40 moonclips and Geco factory ammo. Ones that don't go bang show striker marks, 'haps a bit light but still. If I run the same moon clip over again few or all of the onea that did not go off the 1st time might, or might not.
As said some 500 rounds off the box, gun has been cleaned, no probs so far and now this.

Ideas on what is causing this? Any magic hidden spot on these that I might've not cleaned, wrong moon clips/ammo, etc?

TIA,
-Garth

Lähetetty minun SM-T515 laitteesta Tapatalkilla
 
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Check for a loose strain screw first. It may have worked loose during firing. It's not an uncommon thing on PC guns with reduced power main springs to not go bang if the strain screw is just a little bit loose. Had the same issue with a 627 Pro right out of the box.
 
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Notaglock said:
Check for a loose strain screw first. It may have worked loose during firing. It's not an uncommon thing on PC guns with reduced power main springs to not go bang if the strain screw is just a little bit loose. Had the same issue with a 627 Pro right out of the box.
Click to expand...
Thank you for the hint! Maybe I should've known this, but this is my 1st Smith and I'll stick to that as my excuse ;)
I did tighten the screw, not sure if really loose or not, but tighten it I did.
The way things are going I won't be getting chance to try it out untill Wed. so it remains to be seen if that was the issue or not.

-Garth

Lähetetty minun SM-T515 laitteesta Tapatalkilla
 
Notaglock said:
Check for a loose strain screw first. It may have worked loose during firing. It's not an uncommon thing on PC guns with reduced power main springs to not go bang if the strain screw is just a little bit loose. Had the same issue with a 627 Pro right out of the box.
Click to expand...

The factory does not use reduced power main springs, they use Wolff Type 1 - Factory Standard Power Rib mainspring.

I have seen this issue quite a bit the last two years with brand new PC revolvers, even when the strain screw is screwed all the way in. The strain screw was usually a tad bit to short from the factory and they all needed a new strain screw.
 
Ditto to VikingDude ,bought a 986 when they came out,had misfires say 1-2 out of 14 rounds WW factory 115 . Everything was snug. Put in an extended firing pin still had the odd misfire every so often. Finally noticed that the strain screw was kind of short looking. Put in a slightly longer one and that cleared up the issue.
 
VikingDude said:
The factory does not use reduced power main springs, they use Wolff Type 1 - Factory Standard Power Rib mainspring.

I have seen this issue quite a bit the last two years with brand new PC revolvers, even when the strain screw is screwed all the way in. The strain screw was usually a tad bit to short from the factory and they all needed a new strain screw.
Click to expand...

Someone at the factory must have had an off day on the assembly line. My 627 Pro came with a reduced power, power rib main spring. I assumed it was a full power spring and replaced it with a reduced power, the DA and SA trigger pull didn't change after the swap. I just assumed they were all that way.
 
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I must say that our contact at S&W informed me off this almost 5 years ago, I highly doubt that they have started to use a reduced spring, but it would not surprise me if they did without informing us.
 
The one I found in my 986 was the power rib type, and the strain screw lined up right in the middle of the groove. Of course that made it "short" of the correct bend, so a longer strain screw is needed.
 
Round butt frame strain screws are shorter than square butt screws and this exacerbates the issue of the screw bearing on the rib of the mainspring. Using a set screw from McMaster Carr gives you infinite adjustability without modifying the gun. Also let's you tune to 100% reliability at the range.
 
505Gibbs said:
Please post your results in case the suggestion did not work.
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Gents,

This did the trick. Thank you for the advice!
No more misses, trigger pull seems heavier but coming from Ruger not an issue, at least not for now ;)

Now, is this something y'all check regularly? In other words: does the strain screw loosen over time, and if so do you use adhessives to keep in place?

While we're at it: any other screws etc. that have a tendency to work loose I should be aware of?

-Garth

Lähetetty minun SM-T515 laitteesta Tapatalkilla
 
As the mainspring strain screw does not need to be adjusted or replaced, using a small amount of thread locking adhesive (blue Loctite on this side of the pond) should be ok.
 
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