View Full Version : S&W misfire

March 22, 2009, 10:00 AM
I hope this is the correct place for this.

At the range Friday, my ever trusty S&W Mod 64-1 revolver misfired for the first time since I've had it, over 25 years now. My first thought was old ammo but it also happened with new ammo. The rounds that misfired were indeed hit by the firing pin.

Firing pin is not bent or mushroomed, cylinder slop (movement forward and back) is no more than the day I bought it and the springs all look good. It has only been slightly tweaked, trigger job and a bead blast. Both done by a gunsmith.

I'm looking for any suggestions or ideas since this has me both confused and troubled as this is my carry side arm. It's been well taken care of and kept clean and oiled.

March 22, 2009, 10:06 AM
get different ammo. If it struck the primer and dented it that means that weapon is doing everthing it is supposed to. After hitting the primer the rest is on the ammo to ignite the round down the barrel.

bad batch of ammo/primers. Not your weapon. put in some other ammo and I'm pretty sure it will be just fine.


March 22, 2009, 10:12 AM
That's what I hoping the problem is. Normally it has +P Silver tips in it but that's a bit much for the range, most of the time. On the other hand, one misfire at the wrong time makes for a bad day thus my concern.

March 22, 2009, 03:20 PM
That's the upside to having a wheelgun . You can recover from a misfire a lot quicker than in an auto . The downside is that most autos will give you more rounds when the SHTF .

March 22, 2009, 03:37 PM
In law enforcement we train at 3 and 7 yards because thats where 90% of the time the range will be. That be said we train to dump mags and spin the wheels at that range. If your that close keep pulling the trigger like a WII nintendo controller lol. Any misfire from the revolver will be a memory after the other 4-5 rnds gives the guy some breeze on a summer night

March 22, 2009, 03:43 PM
I don't know very much about DA revolvers.
But,I think there is a screw that holds on end of the mainspring.I have heard of backing off that screw a bit to reduce mainspring tension,thereby reducing DA pull,at the expense off hammer strike.Now,having a screw loose does not seem a good way to tune something,but it may be yours is not tight.

Then,is it possible a lubricant has congealed with age or some other contaminate is dragging down the hammer fall?Could any contamination under the extractors be cushioning the hammer fall? Maybe the hammer is fine but the extractors or something else are causing a soft "anvil."

And,you probably know this,but,with ear protection and all,any trigger squeeze that does not get a boom,its wise to make sure a squib did not plug the bore before squeezing again.

March 22, 2009, 04:12 PM
Point well taken. I've also got a S&W 9MM that produced it's first stovepipe at the range. I've been breaking down, cleaning and all that fun stuff. I even did a bit more polishing on the feed ramp on the 9.

I did compare all the hammers/pins on all 3 .38s and they all look the same, even at moderate magnification, yes, I'm a super geek and have a microscope.

March 22, 2009, 04:42 PM
I had to replace extractor springs in my 1006 twice in 16 years. Now I have spares. :o The mainspring tension is the first thing I would look at also in your revolver. -7-

Mike Irwin
March 22, 2009, 04:53 PM
The very first thing I would check would be the strain screw on the front strap.

If it's loose it can reduce power and cause misfires.

March 22, 2009, 05:45 PM
I gave the main a half turn on the screw, that may help. Also I pulled the side plate off and put a few drops of oil in, but everything looked good. I'm tending to think it was the ammo after all. I bought cheap to get more rounds for the kids to fire.

It's just befuddling to have misfires all of a sudden in the carry sidearm.

Bill DeShivs
March 22, 2009, 06:11 PM
The strain screw should be as tight as you can get it.

March 22, 2009, 07:32 PM
It's close to max now. I know it didn't back out, I put locktite on it at the shop after the trigger job. What a bear it was to change :o I'm thinking a trip to the indoor range is in order soonish just to check it out.

Thanks for all the good words folks!! This is truly a treasure trove of information.

James K
March 22, 2009, 07:55 PM
"I bought cheap." Famous we hope not last words.


March 22, 2009, 08:48 PM
Since your life is on the line I highly recommend you take the gun to a qualified S & W gunsmith to have it checked out. They can mike out all the fittings. The slop on the cylinder may be more than you imagine, there could have developed a bur slowing down hammer fall, there are countless things. Maybe the spring is weak and a stronger after market spring is needed. The gun SHOULD HAVE FIRED and you HAVE TO KNOW WHY IT DIDN'T. Take some of the ammunition with you to the gunsmith.

March 22, 2009, 09:04 PM
Depending on who did the "trigger job", some practitioners loosen or shorten the strain screw.

Therefore, it could be cranked all the way down, but still providing inadequate tension.

If you have an unaltered S&W revolver of the same frame type, check the correct length of the strain screw. A replacement strain screw should be very inexpensive.

Please check back and tell us what it took to fix it--we are all learning a little bit every day.

March 23, 2009, 02:09 PM
Brownell's sells aftermark replacement springs and there are gunsmith books on S & W revolvers. Worth it if you want to get into it that much.

March 29, 2009, 11:20 PM
The strain screw should be as tight as you can get it.Good advice. The kind you WON'T get if you read popular gun magazines.

I've read two articles in the past few months where the author advises loosening the strain screw to lighten the trigger.

One (Stan Trzoniec) said: "For those who like to tinker with the trigger pull, the strain screw is exposed on the inside of the grip frame and can be adjusted within limits."

The other (Paul Scarlata) stated: "While their trigger pulls were on the heavy side, backing off their mainspring adjustment screws a few turns smoothed things out considerably..."

April 3, 2009, 06:49 PM
Two kinds of endshake: crane and cylinder. Both would need to be addressed.

Sounds like the main spring was spun or "cut" (which would be incorrect) since the strain screw appears ok.