Double action light primer strikes

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Mikes5785

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I have a 6” model 66 serial #9K370xx, that I just broke out of mothballs.

I took it to my new club and about half the time if I fired it DA I would get light primer strikes. Firing that same cartridge SA it Would fire properly, anything I need to check?

Thank you

Mike
 
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If you mean the screw that adds tension to the long spring from the bottom of the grip up to the top, that screw was about 1-1/2 turn loose. I turned it in till it was just snug.

I Can’t wait to get it back to the range to check it out

Now I need to get my new Shield Plus and M&P M2.0 squared away

Thank you

Mike
 
Mikes5785 said:
If you mean the screw that adds tension to the long spring from the bottom of the grip up to the top, that screw was about 1-1/2 turn loose. I turned it in till it was just snug.

I Can’t wait to get it back to the range to check it out

Now I need to get my new Shield Plus and M&P M2.0 squared away

Thank you

Mike
Click to expand...


Welcome to the S&W Forums. That is called the strain screw and it applies tension to the main spring, which powers the hammer. Just snug will allow the screw to slowly back out as the spring cycles, you want that screw to be tight. Also, you mentioned that this revolver has been stored for a while. The lubricant on the internal parts may have hardened during storage, so a good cleaning and re-lubing may also be a good idea.
 
Could be if that doesn't solve the issue is that somebody could have shortened the strain screw. I had 2 come to me that way. Bob
 
My 25-2 had same light primer strikes on certain aluminum cased cartridges. Any other cartridges including some 50 year old reloads fired fine. Not buying any more.
 
Tighten the screw more than "just snug" you want it "goodentite "
you don't want it backing out .

Test fire with factory ammo ... reloads can give light strikes when primers are not full seated in the primer pocket .
You end up with a case of "Is it the gun or is it the wonky reloads ??? "
Gary
 
Other posts above have likely zeroed in on the issue. Also note that in double action, the hammer doesn't move back as far before dropping as it does in single action.

Sometimes with marginal hammer strike energy, the problem shows up in double action while single action works fine - just as you observed. I have a 586 with a smoothed and lightened action. Unless I use Federal primers, double action is iffy but single action is trouble free.
 
While the loose strain screw is the most likely cause, since you "just broke it out of mothballs", user error is also possible.

If you don't make sure the trigger goes all the back and hold it there while the hammer falls, the trigger might creep forward just enough to interfere with the hammer fall. This usually happens when you're trying to be extra precise with a DA shot and pause the trigger just when it breaks.
 
I had the same problem w/a LNIB 1973 Model 66 four inch. The strain screw was tight so a gunsmith replaced the main leaf spring. The gun sat in a safe, untouched, since ‘73 when I got it a couple of years ago & it’s been spot on since the smithy fixed it.
 
Hey id love some help with a problem that i cant fix
My 1982 mod 29-2 44 mag is in excellent condition but just regularly strikes light in DA with all factory ammo (so its not the ammo). The mainspring is new, and when tightened all the way, reduces the problem ( maybe 1 out of every 6-8 does not fire) but doesnt make it go away.SA strikes are deep and fire every time. The timing is excellent (changed a hand) and there is no end shake at all. The misfires are not in any particular chamber , but occur in all of them. When checking a case the DA strike is very light and also seems to be slightly off center of the primer, but the hammer seems to go down well with no friction in DA. The gun is cleaned and oil (so no gumming up of parts)
Can anybody think of something?
Thank you
 
You should be able to find a YouTube video on how to tear down your 66. Use a gunsmith specific screwdriver to remove the screws. I use spray carb. cleaner. Ballistol works well for lubrication.
 
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