I think I found the problem!

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au_prospector

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http://www.thehighroad.org/showthread.php?t=723940

I have a S&W model 15-4 experiencing FTF last week. At first I thought it may be my reloads, however now I believe it is the revolver. You guys think the following would cause FTF?

I noticed on my early model 586 there is a very small tension spring between the firing pin and the hammer. The firing pins on these revolvers are mounted on a pivot. The pin on the 15-4 moves freely, the one on the 586 moves under tension from the spring and always returns to the same position. NUMRICH calls it the hammer nose, not firing pin and it is part #48. Part #47 should be the spring, but there is no listing for part #47.

How is the firing pin removed/replaced? I need to get a little spring and insert it on the model 15. I cant seem to locate a part number for this little spring on Numrich, you think S&W can get me one? Is this an easy fix? I am mechanically inclined, but by no means a gunsmith.
 
I had a hammer nose break on one of my S&W m36 clones, and ordered the part from NUMRICH, and took everything down to the local shop. All they did was punch out the rivet holding the hammer nose to the hammer (I didn't have the right size punch at home), and then put the new hammer nose in with the same rivet. I know that most colts have a different way of connecting the hammer nose to the hammer, but if there's a rivet, it's a pretty easy task. Happy Hunting!
 
I doubt that's the problem, as many of the S&W firing pins are not under spring tension.

If it works 100% with factory ammo, then it IS your reloads.

Only if it didn't work 100% with factory would I go looking to "fix" the gun.

I suspect slightly high primers.
 
Is the Hammer spring screw (Strain Screw) fully tightened?
Click to expand...

Yes and it appears to be unaltered. The trigger pull however is very light and smooth. Maybe a pound or two double action and mere ounces single action.
 
au_prospector said:
Yes and it appears to be unaltered. The trigger pull however is very light and smooth. Maybe a pound or two double action and mere ounces single action.
Click to expand...

A 2# DA trigger pull is insufficient for reliability.

If these reloads work in your 586, then I suspect the DA pulls are not the same between the two guns.

Bigtubby asked specifically if the strain screw was screwed in all all the way. Your response "it appears unaltered" does not address his question. Get a flat ground screwdriver and turn the screw clockwise until it stops.

There are a couple reasons for the misfires, the "loose" hammer nose not being among them.

1) your reloads. Try factory ammo

2) an altered mainspring

3) an altered (shortened) strain screw (presuming its screwed in all the way)

Check these items and report your findings. Compare as best you can to the same parts in your 586
 
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Perhaps someone else knows the reason for that hammer nose spring, but S&W apparently put it on all their .357 revolvers (and maybe others). In any case, my 586 has it and so does a Model 27 and 28, and they all have fire lots of rounds without a misfire. Whatever the reason for your misfires, I doubt that spring (unless it is jammed somehow) has anything do with them.

Jim
 
There is a couple of things going on here.

1) My reloads, need to figure them out. The primers are deeply set well below flush. My hand priming tool is putting circle indentations on the primers. I thought I was pushing too hard to seat them. This only happens with small primers, not large ones. RCBS uses different seating rods for each size primer. The seating rod is installed correctly, flat side up against the primer.

The reloads fire without issue in a 586 as well as my dad's 442.

2) The model 15-4 is new to me this year. I bought it because I carried one every day when I was in the Air Force Police. We also carried the Beretta 92. This particular revolver is a police confiscation from Manatee County Florida.
Dont know anything about it beyond that. Trigger pull is extremely light, but I do not have a tool to measure it. Very smooth without a hitch in DA and just a nudge fires it in SA. At first this made me weary, but now I am used to it. The strain screw is tight, it does not look chopped. I do not know what I am looking for in a mainspring. This revolver is 35 years old who knows what life it has had.
 
If the strain screw isn't shortened (I presume you took off the grips for visual confirmation). and is turned in all the way, this points to the mainspring.

But first, try the strain screw from the 586 just to see what difference it might make, if any.
 
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http://www.smith-wesson.com/wcsstore/SmWesson2/upload/other/RevPartsList_Retail.pdf #47 074880000 $0.51 - Revision-6 HAMMER NOSE SPRING. I would replace the main spring & strain screw. The #51 -057700000 $1.32 X HAMMER NOSE RIVET is removed with a punch just a little bigger than the hole. Place hammer on a wood block with a hole for rivet to fall into. But first make a staking tool to shape a new rivet. Tool should fit the old rivet before removing it. Grind a tool by hand if needed. The rivet is soft. After the new hammer nose & spring are in. Place the new rivet in with far side on a metal surface. Stake the side facing you. Turn hammer over, stake the other side. Done. I did a model 28, was easy. Find out what the Revision-6 means?
 
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Whether or not your S&W hammer nose is spring loaded down depends on the model & age of the gun.

Some were, and some weren't.

I have a Model 66 .357 and a 1950 Target .44 Spl. that are.

I have a Model 19 .357, Model 36, Model 49, and Victory model 38 Spl's that are not.

If your gun isn't, the chances are 1,000 to 1 it isn't supposed to be.

Regardless of all that, whatever your problem is, it is not that.

If it never had a spring to start with?
There is no place in the hammer or hammer nose to put one in it now.


Maybe a pound or two double action
Click to expand...
There's your problem right there.

DA pull should be at least 10 pounds, and probably closer to 12+ on an unaltered gun.

Somebody has dinked with the mainspring, or mainspring tension screw if it is already fully tightened.

rc
 
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pictures

I will take some pictures and post them when I get a chance. There is a plate that covers the action. I have under $300 in this. Not great, but no means a disaster.

Is the mainspring easy to replace? $4 bucks is cheap enough.
 
The mainspring is easy to replace and will not require removal of the side plate. Without seeing your strain screw (or the rest of the gun), I would suspect that it has been shortened. I would purchase one of those at the same time as cheap insurance.

And removing the side plate, should you decide to go there, must be done correctly to avoid damage. Don't pry it up. I recommend strongly against removing it unless you get a Kuhnhausen manual and thoroughly familiarize yourself with the working through the book first. It's not a complicated action, but parts can fall out when you take it off and can be damaged by improper handling.
 
"A pound or two double action and mere ounces single action."

I really doubt that. A two pound DA pull would never fire any cartridge, and a SA pull in ounces probably would not stay cocked. FWIW, the standard SA trigger pull on pre-MIM revolvers was almost exactly 2 3/4 POUNDS!

It sounds like someone tampered seriously with that gun, and if they tried to get the pull weights anywhere near 2 pounds and mere ounces, that revolver is highly dangerous and should not be loaded until properly repaired!!

Jim
 
honestly I dont have a gauge

Dont have a gauge, just guessing on trigger pull.

I would say it is less than half of what my 586 is in DA. In DA, my 586 (which is unaltered) has a slight hitch right before the hammer falls in DA. The model 15 is smooth as butter. In SA I would compare the trigger to that of moving my mouse on my rough mouse pad with one finger. Resistance is there, but not much at all.

Thanks for the advice on the side plate, sounds like once the screws are out one would need a suction cup to take the plate off. I was making the assumption the light trigger and smooth pull would be associated with altering the action.

Thanks everyone for good comments. Will pull the grips off and get a picture probably tomorrow. I am not married to this revolver. Just an impulse buy because the price seemed right at the time and I wanted the revolver we carried in the USAF. Admittedly the exact version I carried was probably earlier than the 15 mod -4 which is what this one is.
 
After market "spring kits" may be a problem if installed. I run into a few trade ins that misfired on testing. When i replaced them with factory springs, all was good again.
 
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The S&W Model 15 is the forgotten jewel of the line up and definitely worth fixing.

The problem is likely the strain screw and/or the mainspring. Both are quickly and cheaply fixed. No suction cups required.....

If you haven't taken off the grips yet, how can you report the strain screw is unaltered? Have you tried turning it to see if it'll go in a bit farther? Have you tried swapping out the strain screw from your 586? (I've already suggested that to you 3x, still no response from you about that. :rolleyes: )

I told you before that YOU need to do your part.....and I'm not getting that sense from you at all.

I'm done.
 
You don't need a suction cup to remove the sideplate. Just remove the grips, remove the sideplate screws, turn the gun on its side, sideplate down over a padded surface, and use a piece of wood (hammer handle?) to tap the side of the grip frame opposite the sideplate. The sideplate will fall off.

Jim
 
Tapping it side-plate down is going to do nothing but drive it on tighter.
And scatter some loose parts all over the bench that you might wonder later where they came from.

I concur with doing it over a padded surface.

But do it side-plate UP, and whack the butt of the grip frame DOWN away from it with a wood hammer handle, or hard plastic hammer.
While keeping a thumb on the side-plate to keep it from flying off.

As soon as the impact loosens it from the frame?

Carefully finish removing it with your fingers.
While noting what is where, and how to put it back, when you take it the rest of the way off.

rc
 
Smith & Wesson Side Plate Removal

do it side-plate UP, and whack the butt of the grip frame DOWN away from it with a wood hammer handle, or hard plastic hammer.
This is how i do it, like RC said.
 
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Dont know if it is a fair comparison, but the model 15-4 is on the left and the model 586 no dash is on the right. The position of the mainspring appear identical. The length and position of the strain screw appear identical. More force is needed to manually cock the 586. More force is needed to shoot the 586 in DA. More force is needed to fire the 586 in SA where there is the slight hitch right before the hammer does its job. With the 15-4, there is no sense of movement with the trigger in SA, the hammer just falls.

Also a picture of primed brass. I used a RCBS hand primer with the small primer insert. The half moon indentations do not occur when I am priming for example .44mag where I use the larger primer insert.
 

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