Hammer Strike Issue

[Pit Viper]

I’m not a gunsmith so here’s the issue I’m having. I have OMV in 44 mag and have started getting inconsistent hammer strikes causing misfires.  You can tell the primer has been struck, just not a hard enough strike to fire. Any thoughts on this problem? Thanks.

[Abilene, SASS # 27489]

several possibilities with the gun itself, but I will mention another: your ammo.  If you have any primers not seated fully, that can cause a light strike as it takes some of the hammer fall to push the primer further in.  Those rounds will usually fire on a second try.  Now the "gunsmiths" can chime in. 

[Smokestack SASS#87384]

Things to check:

 

That someone hasn’t added a washer to the lower end of the mainspring. 

 

That the firing pin pin is not crudded up in its bore and moves freely. 

 

That the base pin plunger is not crudded up in its bore and moves freely.  And that it’s not inserted too deeply. 

 

That the transfer bar is raising to a high enough position every time the trigger is pulled. And that it’s not broken or dragging in its mortise. 

 

That the hammer plunger is not bent or crudded up in its bore and that it moves freely. 

 

 

 

 

 

 

 

[Garrison Joe, SASS #60708]

Check that you are not retarding the hammer fall with either one of your thumbs.

[Dusty Devil Dale]

9 hours ago, Garrison Joe, SASS #60708 said:

Check that you are not retarding the hammer fall with either one of your thumbs.

Speaking for myself, thumb interference or poor hammer release is by far the most common cause of light primer hits, particularly if the misfiring occurs  while slip-hammering, and doubly so on short-stroked pistols.  Even the slightest  "following back" of the hammer with your thumb removes a huge fraction of the hammer's energy.   I have to be very sure that my thumb properly slides off the side-rear of the spur, and doesn't move back forward the slightest bit, as I let it go.  In hurrying, I sometimes make that mistake and have to go around the cylinder again.  

 

I would ask:  On the second pass around, do the rounds fire?  If not, then check all of the other factors described above by others, and try a softer primer, like Federals. 

 

They do make and sell extended firing pins for Old and New Vaqueros, but putting them in is not an easy thing.  First, I would try a heavier hammer spring.  

 

Good luck.  It took me quite a while to finally realize and admit that the problem with my Vaqueros was..... ME.  Cheap solution though! 

[Widder, SASS #59054]

9 hours ago, Abilene, SASS # 27489 said:

several possibilities with the gun itself, but I will mention another: your ammo.  If you have any primers not seated fully, that can cause a light strike as it takes some of the hammer fall to push the primer further in.  Those rounds will usually fire on a second try.  Now the "gunsmiths" can chime in. 

 

Like Abilene,  I will leave the gunsmith comments to the gunsmiths.

But I agree about checking that your primers are FULLY seated.....  not just seated flush.

 

A flush fitting primer will still allow the cylinder to rotate but it won't tell you if the primer is

FULLY seated, which normally is a couple .000's lower than the rim.

 

Plus, its the easiest and cheapest thing to check and fix, if its the problem.

 

..........Widder

 

[Chert Rock Chuck]

9 hours ago, Garrison Joe, SASS #60708 said:

Check that you are not retarding the hammer fall with either one of your thumbs.

Yep, I'm guilty.

 

[Yul Lose]

1 minute ago, Widder, SASS #59054 said:

 

Like Abilene,  I will leave the gunsmith comments to the gunsmiths.

But I agree about checking that your primers are FULLY seated.....  not just seated flush.

 

A flush fitting primer will still allow the cylinder to rotate but it won't tell you if the primer is

FULLY seated, which normally is a couple .000's lower than the rim.

 

Plus, its the easiest and cheapest thing to check and fix, if its the problem.

 

..........Widder

 

Good advice. For a time not long ago I had two or three light primer  strikes every stage and couldn’t figure out what was going on and then I discovered a broken part on my Dillon 650 that was not allowing primers to be seated fully. I sent the press to Dillon and when I got it back in virtually new condition the primers would fully seat, haven’t had a light primer strike since.

[Dusty Devil Dale]

I discovered a broken part on my Dillon 650 that was not allowing primers to be seated fully. I sent the press to Dillon and when I got it back in virtually new condition the primers would fully seat, haven’t had a light primer strike since.

 

What part was it on the 650? 

 

On my press, I have to be sure that the shell plate is torqued down properly, so it can rotate freely, but cannot flex upward.  The plate itself must also be perfectly flat (not bent or warped by using too much pressure, resizing difficult rounds.)  If the shell plate can flex upward at all, then the primers don't get seated properly, because the primer seating pin coming from below, is limited in its upward movement.  

[The Original Lumpy Gritz]

10 hours ago, Pit Viper said:

I’m not a gunsmith so here’s the issue I’m having. I have OMV in 44 mag and have started getting inconsistent hammer strikes causing misfires.  You can tell the primer has been struck, just not a hard enough strike to fire. Any thoughts on this problem? Thanks.

What mods have you done to the gun?

Will the gun fire with factory ammo?

When was the last time you took the grips off and flushed out the inside of the gun?

OLG

[The Original Lumpy Gritz]

10 hours ago, Smokestack SASS#87384 said:

Things to check:

 

That someone hasn’t added a washer to the lower end of the mainspring. 

 

Mainspring as in hammer spring?

That washer will increase the hammer tension for a better 'smack' on a Ruger.

OLG

 

 

[Yul Lose]

25 minutes ago, Dusty Devil Dale said:

I discovered a broken part on my Dillon 650 that was not allowing primers to be seated fully. I sent the press to Dillon and when I got it back in virtually new condition the primers would fully seat, haven’t had a light primer strike since.

 

What part was it on the 650? 

 

On my press, I have to be sure that the shell plate is torqued down properly, so it can rotate freely, but cannot flex upward.  The plate itself must also be perfectly flat (not bent or warped by using too much pressure, resizing difficult rounds.)  If the shell plate can flex upward at all, then the primers don't get seated properly, because the primer seating pin coming from below, is limited in its upward movement.  

The casting that the handle and the shaft connect to.

[Bucky Buckskin]

Wore out main spring 

[Dusty Devil Dale]

9 minutes ago, The Original Lumpy Gritz said:

Mainspring as in hammer spring?

That washer will increase the hammer tension for a better 'smack' on a Ruger.

I've never seen a gun with a washer installed.  The washer would need to be machined PERFECTLY flat, in order to not deflect part of the spring energy laterally.  

From a mechanical engineering standpoint, it would be far better just to replace the spring with a higher force one, rather than introduce a new variable of another movable part that could diffuse a part of the spring's responsive force.   

 

[The Original Lumpy Gritz]

Just now, Dusty Devil Dale said:

I've never seen a gun with a washer installed.  The washer would need to be machined PERFECTLY flat, in order to not deflect part of the spring energy laterally.  

From a mechanical engineering standpoint, it would be far better just to replace the spring with a higher force one, rather than introduce a new variable of another movable part that could diffuse a part of the spring's responsive force.   

 

I have used #10 AN washers, many times over the years for this issue with 100% success.

It's a KISS type of fix........

OLG

[Yul Lose]

3 minutes ago, Dusty Devil Dale said:

I've never seen a gun with a washer installed.  The washer would need to be machined PERFECTLY flat, in order to not deflect part of the spring energy laterally.  

From a mechanical engineering standpoint, it would be far better just to replace the spring with a higher force one, rather than introduce a new variable of another movable part that could diffuse a part of the spring's responsive force.   

 

.???

[Cheyenne Ranger, 48747L]

added a cheap washer to my Marlin hammer spring--that's all it needed to be totally reliable.  without it I would get a light hit now and then

 

and yes I know the OP is speaking to revolvers

 

[Dusty Devil Dale]

50 minutes ago, Yul Lose said:

55 minutes ago, Dusty Devil Dale said:

I've never seen a gun with a washer installed.  The washer would need to be machined PERFECTLY flat, in order to not deflect part of the spring energy laterally.  

From a mechanical engineering standpoint, it would be far better just to replace the spring with a higher force one, rather than introduce a new variable of another movable part that could diffuse a part of the spring's responsive force.   

 

.???

Question? 

 

The physics of coil spring energetics is complex.  The spring is usually designed to be a straight cylinder, with near perfectly flat ends, so that (nearly) 100% of its force is delivered along its long axix.  If you flex a spring slightly in a curve, it will still apply force, but it's linear force is proportionately less.  There are formulas for computing that force vector reduction. 

 

A weak-point in the Vaquero spring operation is therefore the flatness of the anvil, against which the flat end of the spring rests.  If it is tilted, or not a flat supporting surface, it will very slightly bend the spring and alter its force vector (that is true even with the spring being loosely captured over the center rod).  The same reduction would be common to an added washer, intended to pre-apply compressive force to the spring.  If the washer is not in perfect alignment, and is not quite thick, so as to add more force than it diffuses, it may actually reduce the spring's force.  The deflection loss is admittedly a very, very small energy difference, but so is the amount of energy/force being added by the thin shim (washer).  

 

Has anybody actually measured the increase in spring force with and without a washer?  If it causes the spring to flex slightly off center, then I bet the change in force actually becomes very minimal.  

 

 Again, it would be much more predictable to simply substitute in a (very cheap) higher force spring.  

 

 

 

[The Original Lumpy Gritz]

9 minutes ago, Dusty Devil Dale said:

Question? 

 

The physics of coil spring energetics is  extremely complex.  The spring is usually designed to be a straight cylinder, with near perfectly flat ends, so that (nearly) 100% of its force is delivered along its long axix.  If you flex a spring slightly in a curve, it will still apply force, but it's linear force is proportionately less.  There are formulas for computing that force vector reduction. 

 

A weak-point in the Vaquero spring operation is therefore the flatness of the anvil, against which the flat end of the spring rests.  If it is tilted, or not a flat supporting surface, it will very slightly bend the spring and alter its force vector (that is true even with the spring being loosely captured over the center rod).  The same reduction would be common to an added washer, intended to pre-apply compressive force to the spring.  If the washer is not in perfect alignment, and is not quite thick, so as to add more force than it diffuses, it may actually reduce the spring's force.  The deflection loss is admittedly a very, very small energy difference, but so is the amount of energy/force being added by the thin shim (washer).  

 

Has anybody actually measured the increase in spring force with and without a washer?  If it causes the spring to flex slightly off center, then I bet the change in force actually becomes very minimal.  

 

 Again, it would be much more predictable to simply substitute in a (very cheap) higher force spring.  

 

 

 

 

I have-It didn't go bang every time. SOooooooooooooo, I added said washer-Now it goes bang every time....... 

You have more issues with the spring drag'n on the sharp edges of the hammer strut, than that 'anvil' will ever cause.

Quality springs are not cheap-Nor should they be......

This ain't brain surgery-

OLG

 

[Dusty Devil Dale]

1 hour ago, The Original Lumpy Gritz said:

You have more issues with the spring drag'n on the sharp edges of the hammer strut, than that 'anvil' will ever cause.

Quality springs are not cheap-Nor should they be......

This ain't brain surgery-

No specific disagreement with you.  The effect of an uneven base is real but it is, in fact, minor.  Whether or not the gun goes bang every time is an ultimate performance test.  If the problem goes away, it is fixed.  I just personally prefer the simplicity of fewer parts in the chain affecting things.  

 

I have half of a quart-size zip lock bag a full of different strength Vaquero (Old and New) hammer springs made by Wolff.  They're quality products that range from 14 to 24#.  If any cowboy (or cowgirl) pard honestly can't afford the $22 to buy a set of 3 from a vendor like Brownells, then  PM me and I'll be happy send you the weight you want, as long as they last. (No kidding.) 

After buying and trying all different weights, I personally went back to stock 23# springs, trying to reduce lock response time.  But I'm a old guitar picker, with fairly strong hands.  For somebody else, the heavier springs might  not work out.  

[Dusty Devil Dale]

2 hours ago, The Original Lumpy Gritz said:

You have more issues with the spring drag'n on the sharp edges of the hammer strut, than that 'anvil' will ever cause.

Hard to say for every case.  A side- flexed spring loses a lot of force. 

But in general I will agree the strut friction can be greater. 

 

Folks should long ago have smoothed their hammer struts, to reduce their coefficient of friction and make the hammer pull more consistent.   A couple minutes with 320-grit, followed by light buffing will do it.  They come from Ruger and aftermarket rough as concrete.  

 

---And while you have things disassembled to polish the strut, why not just rub the "anvil" against the 320, backed by a flat surface, just to get it good and flat--just for the sake of physics/rocket science.  

Thanks for the interchange. 

DDD

[The Original Lumpy Gritz]

When you are 'tuning' 2 guns to be the same.

It's best to call Wolff directy, and specifically ask the order taker to 'pull' the spring order from the same lot run.

OLG

[Smokestack SASS#87384]

5 hours ago, The Original Lumpy Gritz said:

Mainspring as in hammer spring?

That washer will increase the hammer tension for a better 'smack' on a Ruger.

OLG

 

 

The problem is not the washer, if there is one, but the placement. If it’s at the lower end of the spring, it can shift and pinch the strut causing more drag. If you’re going to shim a spring, always do it on the non moving end. 

[The Original Lumpy Gritz]

1 minute ago, Smokestack SASS#87384 said:

The problem is not the washer, if there is one, but the placement. If it’s at the lower end of the spring, it can shift and pinch the strut causing more drag. If you’re going to shim a spring, always do it on the non moving end. 

I have found on the Rugers, by put'n the 'shim' at the bottom of the strut.

You have less issues with the trigger return spring if said spring has had the 'legs' arched some to reduce tension.

Putting the 'shim' at the top of the strut, is easier to do for sure...........Less stuff to hold in alignment, when you compress the spring.

 

OLG