Doesn't Go Bang

[Eliduc]

I'm trying out a S&W 586 that I can get for a good price. It seems to be in exceptional condition except that it misfires more than it doesn't when firing 38's. It seems to be ok with 357 mags but I only had a handful to shoot. To me it practically has a hair trigger in single action and a pretty light trigger pull in da. I'm thinking someone might have modified the mainspring screw. if there is much pressure at all on the trigger the hammer doesn't want to catch when fully cocking in single. I noticed the 357 cartridge bases seem to be just a hair thicker than my 38's. Could that be why they are firing and the 38's aren't?

[CHeatermk3]

You could try tightening the screw that puts tension/takes off tension(don't remember which way to go) this should change the pull of the trigger and a heavier pull (more spring tension) may be all that's required.

Someone who actually knows should be along shortly.

[Der Gebirgsjager]

If there is a difference in the case head thickness that certainly could be the problem. One would think in this modern age that all would be the same, but there is sometimes a difference among brands; so trying a different brand of ammo might cure your problem. If you have a reliable micrometer or caliper you should be able to measure any difference that exists. Another possibility, since some fire and some don't is the primers.
Again, some brands and lots are more sensitive than others. If you're shooting reloads then a test with factory ammo would be more informative.

[tazman]

Since the trigger pull is so light, I suspect someone got the spring tension screw turned out too far or shortened it too much. If you can tighten it, do so as a first step. If you can't, then you might try to put a small metal cup over the end of it to see if increasing the tension improves things. It is also possible the main spring has been changed for one that is too light. You might also look to see if the sear area has been messed with. It takes very little work on those areas to make them so they don't work properly.
Too light a spring could cause all of your problems.

[knifemaker]

I'm willing to bet that someone backed out the mainspring tension screw. It is located on the front bottom of the grip frame. Turn it clockwise to apply more tension to the hammer mainspring.

[ratboy]

Since the trigger pull is so light, I suspect someone got the spring tension screw turned out too far or shortened it too much. If you can tighten it, do so as a first step. If you can't, then you might try to put a small metal cup over the end of it to see if increasing the tension improves things. It is also possible the main spring has been changed for one that is too light. You might also look to see if the sear area has been messed with. It takes very little work on those areas to make them so they don't work properly.
Too light a spring could cause all of your problems.

you can use a spent primer cup without the anvil.
also check to see if the main spring has a rib in it. if it does, then it is probably a wolf main spring.
i have had to use a longer strain screw in almost every smith i have that spring in to get consistent ignition.
the screw end up in the rib and no longer preloads the spring as much as the original
they claim its an upgrade but seems to cause more problems than it solves.

[osteodoc08]

There have been known issues with the newer 586s with light primer strikes. I had to send mine in. There was also a recall on the no dash and -1 to replace the firing pin bushing. If it was done already there will be an M stamped at the serial number.

[clum553946]

May have a reduced power mainspring, if the above suggestions don't work, you might try a standard power spring.

[NC_JEFF]

If you can get this 586 at a good price do it. The light primert strike problem will be easy to cure.

[44man]

Some had a problem with the firing pin not extending long enough but that gun sounds like it was fooled with. The strain screw should never be filed off or backed out. The hammer spring should not be lightened for any reason. To do so will ruin accuracy.
Not many shoot double action anyway and if you do you should understand the hammer stroke is shorter double action then SA.

[gtgeorge]

I think you have received a lot of great advice here but wish to add my old 66 no dash would rarely fire double action but did better single. Someone had used a lube in it that became hard and sticky that was a nightmare to remove from the works with carb clean or brake clean but once cleaned out works flawlessly. It had set up for several years. I am sure yours may be fixed with the advice above though.

[Shooter6br]

I get misfires with a Model 10 HB with Winchester primers.. Load with Federal if you can find them. My Mod 10-6 was a police turn in. Light sweet trigger. Also check strain screw

[44man]

Worst ever for a gun is WD40. nothing will dissolve it after it hardens.
But to need a different primer to fire does indicate something is wrong. Sorry, it is not the path to accuracy.

[Mal Paso]

Worst ever for a gun is WD40. nothing will dissolve it after it hardens.
But to need a different primer to fire does indicate something is wrong. Sorry, it is not the path to accuracy.

WD40 is the worst thing ever for anything.

Get the gun! Factory Mainsprings are like $7 and firing pins $4-15.

I tried the Power Rib and several other aftermarket Mainsprings. That Factory S&W Mainspring is hard to beat. It is better tuned to the action.

Now the Redhawk, I have to keep a bag of new Factory springs and put a new one in any time I have it open.

[Petrol & Powder]

I'm willing to bet that someone backed out the mainspring tension screw. It is located on the front bottom of the grip frame. Turn it clockwise to apply more tension to the hammer mainspring.

Turn it ALL the way in until it bottoms out, that's where it belongs. If it has been shortened, placing a spent primer over the tip of the screw will help.
This issue came up in another thread. The strain screw is NOT an adjustment for trigger pull weight. The 586 is a good gun and if that is the only issue I would buy that gun. The mainspring is an easy fix.

[gtgeorge]

Worst ever for a gun is WD40. nothing will dissolve it after it hardens.
But to need a different primer to fire does indicate something is wrong. Sorry, it is not the path to accuracy.

Thanks for that. I never cared for WD-40 and always wondered what that was gumming my revolver up. I wonder how long it takes to gum up?

[44man]

WD-40 is the worst stuff ever made. I used to spray and clean my saw bases with it and they all rusted very fast. Not fun to have my radial saw base rust away.
Farmers in PA buy the stuff in 55 gal drums for farm equipment and they all have rust problems. They spray into guns and I had to fix them. Firing pins in bolt guns frozen in and nothing I would soak in would remove it, had to use mechanical means.
NEVER spray in a door lock! I did locksmith work too so use graphite lube only.
Do NOT spray innards of a S&W with the junk. It gets like super glue.
WD-40 is a water displacement ONLY but what is left is EVIL.
Use Birchwood-Casey Barricade or Sheath instead.

[lar45]

Like everybody said, the main spring tension should be the first place to work on.
Your description of the action makes me wonder if someone messed with the sear also.
Leave the gun empty, cock the hammer then put some forward pressure on the hammer(while keeping your finger off the trigger) to see if it will jump the sear.
If so you need to take it to a smith and get it corrected before shooting it.

[thegatman]

WD-40 is the worst stuff ever made. I used to spray and clean my saw bases with it and they all rusted very fast. Not fun to have my radial saw base rust away.
Farmers in PA buy the stuff in 55 gal drums for farm equipment and they all have rust problems. They spray into guns and I had to fix them. Firing pins in bolt guns frozen in and nothing I would soak in would remove it, had to use mechanical means.
NEVER spray in a door lock! I did locksmith work too so use graphite lube only.
Do NOT spray innards of a S&W with the junk. It gets like super glue.
WD-40 is a water displacement ONLY but what is left is EVIL.
Use Birchwood-Casey Barricade or Sheath instead.

I know just what you mean. Stuff is awful.

[ole 5 hole group]

Ole Hoppe's #9 wasn't very friendly either, if you liberally dabbed it on in all the wrong places I thought it was good for everything and after 10 to 30 years my single shots were hard to open, rifle triggers were gummed up, firing pins were gummed up etc.


I used Brownells aerosol degreaser - the one that tried to destroy your lungs - I forget the name now but they replaced it with the aerosol TCE degreaser, which I now use for a few projects. I find it better than brake cleaner but it costs more as well.

There are now a couple different types of WD-40 and from what little I've heard and read about the WD-40 Specialist is as good as about anything on the market today. I'm a little gun shy of it so I'm a believer in One-Shot HD-Extreme, having switched to it from Ezzox.

AS to the OP's question - sure sounds like someone backed out the strain screw - as Petro & Powder suggested - turn that sucker all the way in and leave it there.