J-Frame hammer "bobbing" - The final answer

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I am considering having the hammer spur on my 637 "bobbed".

However I am REALLY confused as to the reliability issues resulting from this modification.

On this and other forums, I have read warnings about reliability issues that may result.

So, I went to the "source" and sent an e-mail to Smith & Wesson asking for their advice/recommendation. Their response was "you might consider sending the gun in for that modification - lightening the hammer could cause misfire"

That confused me so I asked if the factory modified the original hammer or installed a new one. To this their response was "they actually polish the existing hammer" at a cost of $56 with a 5 week turnaround time.

So, now to my questions:

If this modification is inadvisable, why would the factory do it for $56, given the potential liability risks?

Does the factory have secret knowledge about this modification that mere mortals (local gunsmiths) do not possess? If so, what might it be?

How much of the hammer spur can be removed without adverse effecte, i.e. light primer strikes? This assumes the use of the factory mainspring or the 9lb Wolff replacement.

I would appreciate all input, but particularly that of professional gunsmiths.

Perhaps we can finally put this issue to rest.

Thanks,

red

 

[bountyhunter]

Removing the hammer spur reduces the mass of the hammer, which reduces striking force for a given spring weight. The "polish" comment is interesting, I wonder if the person meant that they would polish the hammer sides and the boss pin to reduce hammer friction (which would tend to increase striking force). That's a pretty standard part of an action job done to smooth the trigger pull anyway. I'll wager the $56 includes smoothing out the works.

I can think of a many ways they might be "getting back" the lost strike energy due to lightening the hammer. They could have some stiffer springs specifically for use with lightened hammer or they could be using a shim in the coil mainspring to effectively coompress it a bit more than stock. They may be not telling you everything so you won't try it yourself.

One thing I am sure of, whatever S+W does to give you a snub with the hammer trimmed will have passed their lawyers and will likely be safe. I am not so sure that would be true for a local gunsmith. I also know that designs with coil mainsprings are known to be more prone to have light strike misfires. To keep the pull manageable, the spring weights are designed closer to the edge. Coil springs can stack, which means the coils expand and get side by side which reduces spring force and you get misfires. Taurus guns are notorious for this.

 

[Old Fuff]

There is a lot more to "bobbing" a hammer spur then simply cutting it off. First check for "endshake" (back & forth movement of the cylinder as opposed to rotational play) and correct it as necessary. Then determine what the firing pin protrusion is by checking with feeler guages. For extra insurance, use the same mainspring that are used in rim-fire "J" frame models.

Last but not least, consider selling or trading the gun for one of the models that has an enclosed or shrouded hammer.

After all this has been said, I have an early model 60 that I've carried for years that has a bobbed hammer. It has never failed to go bang!

 

[Johnny Guest]

Callow youth . . . AND middle age.

Ah, the heedlessness of years past.

With all respect due to bountyhunter - - - I generally concur with the sense of his comments, up to the last paragraph. I can neither confirm nor refute his comments there, which are outside my experience.

My personal observations: The only time I've seen this type revolver fail to ignite primers properly has been when the mainspring was excessively lightened - - both with hammer spur is bobbed, and when left intact.

I have personally owned at least six revolvers from which the hammer spurs have been cut. On my first Chiefs Special, back in the middle 1960s, I let my enthusiasm overload my knowledge and cut too much off the coil spring, besides bobbing the hammer. I bought two new springs and cut one-and-a-half coils from one. I tested it with three different brands of primers, and several factory loads, and that revolver remains in service today.

I realized that I was pressing my luck, and have never cut coil mainsprings since then. I do NOT endorse amateur hammer bobbing unless the "bobber" is willing to engage in extensive testing, and accept that he (she?) may need to replace a hammer entirely.

I cut the hammer spur from the model 37 in my pocket at this moment. My elder son has another I bobbed. My former wife has my originally modified model 36. I've also cut down various K frame hammers, and a few D frame Colts, which of course don't have coil mainsprings. My Colt Agent has a spurless hammer, modified by an earlier owner, and I tested it throughly before I trusted it. I do subscribe to the concept, but far less casually than in the past.

Best,
Johnny

 

[Mike Irwin]

You just got what some of us like to call the Smith & Wesson Non Answer, Send Us Money, answer.

They didn't address your question about reliability issues, they don't tell you how THEY can do it better so that reliability isn't compromised (Maybe they use a heavier polish?), they just say send money, hammers, and weeks, the hammer has hit the primer... (wow that was a bad Zevon wannabe...)

The fact remains, though, that these days I would NEVER send a gun to S&W for repair. I've heard too many horror stories from way too many credible sources (including quite a few here) to even want to go down that road to hell.


The simple answer to the burning question of whether or not removing the hammer spur will cause reliability problems is....

Maybe.

There are so many variables involved that it's not even funny. There is simply no single, or simple, answer that will cover all of your questions. It can be very different for each gun involved because of the natural variations that make each firearm an individual.

What is advisable, however, is that if you do decide to remove the hammer spur is to have a action polishing done to remove any possible friction points and allow the hammer to achieve maximum velocity.

If you've got a lightened mainspring, you may have to ditch it so that the hammer gets as much velocity as possible to overcome the loss of mass.

Finally, if you do decide to have this done, or do it, I'd put a MINIMUM of 500 rounds of your personal protection ammo through the gun before I'd even begin considering it for CCW duty.

 

[Mike Irwin]

"I'll wager the $56 includes smoothing out the works."

When it comes to S&W's service department these days, and the stories I've heard, I wouldn't even wager that the $56 includes getting the hammer spur whacked off the hammer.

 

[Jim K]

One little trick that one might want to try is to not cut the mainspring, but to reduce tension by "rolling" it on a belt sander. I have done this a lot and find it leaves the spring more reliable than cutting coils.

But if you are going to play around with this, buy two or three springs (or four or five) and be prepared to lose at least one.

How to do it? Take a rod a tad smaller than the inside diameter of the spring. With the spring on it and able to turn freely, bring the side of the spring up to a moving belt sander. Let the spring touch and turn for a couple of seconds until the coils are slightly flattened on the outside.

Then try it with live rounds. (Don't use primed empties, you can't gauge primer indentation.) If the pull feels OK and works, and primer indentation is normal, you can try another few seconds of "rolling". If you go too far, well that is what the other springs are for.

All by feel and instinct, which is why I can't tell you to "cut off 1.3765 coils", or some such, like some of the books do.

Of course, this involves taking the gun apart and putting it together several times, which is time consuming and labor intensive, which is why good gunsmiths (or even bad gunsmiths) charge you lotsa bucks for this kind of thing.

Jim

 

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J-Frame hammer "bobbing"

Thanks to all who have offered advice/opinions.

Now,as I did on the S&W forum, I will stir the pot some by asking if hammer spur snag is a significant enough problem to necessitate hammer "bobbing".

On another forum, I saw the following comment -sorry that I cannot attribute it to it's originator - "One trick you can try is to practice drawing with your thumb against the hammer spur. As soon as the gun is clear, simply drop the thumb to normal shooting position. The thumb works like a ramp to prevent snagging - safe, simple and with a bit of practice just as fast as any other draw."

After some practice, this technique seems very workable.

Comments?

Thanks again,

red

 

[Master Blaster]

On another forum, I saw the following comment -sorry that I cannot attribute it to it's originator - "One trick you can try is to practice drawing with your thumb against the hammer spur. As soon as the gun is clear, simply drop the thumb to normal shooting position. The thumb works like a ramp to prevent snagging - safe, simple and with a bit of practice just as fast as any other draw


I think you may have read my post on TFL. I have a model 36 made in 1974, which I carry in a desantis pocket holster. I practice this technique, and it works perfectly.

Rather than bobing the hammer completely you could round and smooth the spur and slightly bevel and smooth the bottom edge of the rear of the spur, that will reduce the possibility that it will snag. I saw this technique on the Wilson combat site where they do a carry tune to the S&W snubbie, rather than removing the spur they round bevel and smooth it to make it snag free.


The NRA instructor at our club has a J-fram he bought new in 1957, he dropped it in about 1970, and the hammer spur broke off, he filed and smoothed it and still carries this gun, and uses it in training class, it probably has about 1 million rounds through it judging by the amount he uses it to train folks for CCW, and it quite reliable, I asked him about it and he has lightened the trigger return spring as well, but not the hammer spring!!!!

He said since 1970 it has been 100% reliable.

 

[Mike Irwin]

I simply bought an 042 -- a Centennial Hammerless.

 

[Old Fuff]

There are at least two problems with hammer spurs on “deep cover†handguns. One has to do with getting the hammer snagged on clothing during the draw, and the other has to do with the checkering on the hammer spur abrading clothing – sometimes to the point where it snags the gun.

A properly designed holster can take care of the second point, and yes – you can use your thumb to cover the spur during the draw.

A lot depends on what kind of gun, how it’s carried, and how it’s concealed. The choice of clothing (or whatever) can be critical.

Another related issue concerns certain lawyers that bring wrongful death or injury lawsuits after a deliberate shooting – insisting that it was accidental because the defendant cocked his revolver rather then shooting it double action. The difference is a trigger pull around 3 pounds rather then 12. In court of course the lighter pull is a “hair trigger.†Enough of this happened so that some major police departments had regular service revolvers converted to double-action only. On an individual basis I consider such a suit to be possible, but not probable. But then these days one never knows.

So far as small revolvers go, I think the best answer is one with an enclosed or shrouded hammer. When these weren’t available the only answer was to de-horn the hammer if you didn’t want the spur. That’s still the case with mid and large frame guns, and in both the hammers have enough mass and weight so removing the spur is a moot point so far as reliability goes.

Between the early 1950’s through the middle 1990’s I modified a lot of revolvers of all sizes and many makes. None that I know of ever had any ignition problems. But since the enclosed hammer/shrouded hammer models are available and offer additional advantages over modified conventional revolvers why not use them?

 

[bountyhunter]

With all respect due to bountyhunter - - -I can neither confirm nor refute his comments there, which are outside my experience.

I read that at least eight times and still have no idea what it means. If what I said was outside your area of experience, what are you trying to say?

What I said was:

"One thing I am sure of, whatever S+W does to give you a snub with the hammer trimmed will have passed their lawyers and will likely be safe. I am not so sure that would be true for a local gunsmith. I also know that designs with coil mainsprings are known to be more prone to have light strike misfires. To keep the pull manageable, the spring weights are designed closer to the edge. Coil springs can stack, which means the coils expand and get side by side which reduces spring force and you get misfires. Taurus guns are notorious for this."

Basically, I was saying that SW's recommendations and actions will be somewhat reflective of "lawyer proofing", ie leaning toward the conservative side. Your local gunsmith will put in whatever springs you tell him to and then tell you it's your ???.

As to coil mainsprings being more prone to light strikes than leaf spring designs, that's pretty much a known fact even for SW snubbies as given by published test reports. "Stacking" is a long time and well known problem which a leaf spring can not have. As for Taurus being known for coil-related light strikes, read the test reports. Taurus still is using coil springs in most of their larger frame guns which SW got away from years ago. Coil mainsprings are not as good as leaf springs for reliable hammer powering.

 

[Mike Irwin]

"Taurus still is using coil springs in most of their larger frame guns which SW got away from years ago."

I don't know what Taurus is using these days, but Smith & Wesson has NEVER used coil main springs on any of their guns other than the improved I-frames and the successor J frames.

I don't know what the new X frame uses.

 

[Johnny Guest]

Perhaps we're both being a bit unclear - - -

bountyhunter wrote:

I read that at least eight times and still have no idea what it means. If what I said was outside your area of experience, what are you trying to say?

I meant to write that I agreed with your first two paragraphs, but could not agree with the third. I did not want to argue about that part.

Not sure what you mean by "Coil springs can stack, which means the coils expand and get side by side . . . ." My only experience with the term "stacking," pertaining to revolvers, is the sensation of increasing stiffness found in (mostly) Colt revolvers with leaf mainsprings. Are you saying "stacking" means that some of the spring coils actually get down inside other coils? I've opened up a lot of J-frames, and been present when REAL gunsmiths have worked on a lot more, and I've never seen this phenomenum nor heard it mentioned. J frame mainsprings are mighty stiff, and I can't picture such an effect.

As to coil mainsprings being more prone to light strikes than leaf spring designs, that's pretty much a known fact even for SW snubbies as given by published test reports. "Stacking" is a long time and well known problem which a leaf spring can not have. As for Taurus being known for coil-related light strikes, read the test reports. Taurus still is using coil springs in most of their larger frame guns which SW got away from years ago. Coil mainsprings are not as good as leaf springs for reliable hammer power.

(Emphasis added.)

On that point, I'll have to disagree. I detailed my personal experience with reducing number of spring coils on a Chief, so of course I am aware that this can cause light strikes. I can't agree that this is a more common effect with coil springs than leaf springs. I've read several little "tuning tips" regarding grinding leaf mainsprings thinner to reduce trigger pull. And backing out the strain screw on the mainspring used to be a common thing. And even my old hero Skeeter Skelton mentioned placing a pin punch or drill bit in the angle of a Colt V-mainspring and slowly cocking the hammer, to bend the spring slightly for lesser tension. Much as I admire Skeeter and his memory, I think he was responsible for the ruination and replacement of many Colt springs with that article.

Could you please provide some reference to the test reports you mention? I'm always trying to expand my knowledge on this topic, and I apparently missed these entirely.

Easy research: Please do a search on "Light strikes," both on THR and The Firing Line. I believe you'll find more references to this problem with leaf mainsprings than coil springs. I agree with Mike Irwin, in that I know of no other S&Ws with coil mainsprings. Might you be thinking of the Ruger revolvers?

My remarks about callow youth/heedlessness of years past referred to MY activities, as detailed a bit later in that post.


Best,
Johnny

 

[280PLUS]

i vote hammerless too,,,

what snag problems?



in case you don't know,,,

some hammerless can still be shot SA (my s&w 332 eg.)

theres a dead spot in the pull between cocking and releasing the hammer right after the cylinder locks in place

with a little practice this spot is very easy to find

it does not affect DA shooting, (with mine anyways)

m