Hopefully not a repost, TK Custom has created an Adjustable Coil Spring Speed Hammer Kit for S&W N-Frames for $300.

Looks interesting: Adjustable Coil Spring Speed Hammer Kit for S&W N-Frame - TK Custom

It looks to be well made but I'm not sure what the point is.

Looks like it is only offered in DAO?
FWIW one like they put on the large-frame Astra revolvers would be even cooler - adjustable preload means you don't have to replace springs. They only made it with 4 adjustment "steps" but a thicker ring (allowing for a deeper "step") would allow at least a half a dozen different settings.

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Send lawyers, guns & money...

I'll keep mine stock. Seems to be a lot of $$$ for nothing gained.

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S&W Accumulator

Adjustable trigger pull from 6-9lbs per shooter preference and ammo used seems a nifty capability.

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Pickpocket

A used 624 I had years ago had a coil
hammer spring; not adjustable however.
After using it for a while, I ended up
replacing it with a standard flat spring.

At one time the coil spring for S&Ws
was all the rage---but I believe for a
very short time.

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Ubi Est Mea

I've never used one of these so it's a little hard to know but it seems that you would be changing the pull weight while creating a stacking issue with the coil spring. If reducing the double action pull weight is the goal, you can do that by changing the main spring and the rebound spring. The pull would be smoother and you can do it at 10% of the cost.

Ya if you want to get the trigger pull down on a N frame it isn't $300 worth of hard. Plus, I don't care how you do it it takes a certain amount of force to ignite a primer and that force plus enough to turn the cylinder, has to come from your finger in a double action revolver. It would be difficult to make a 100% reliable on all primers 6# trigger pull

Plus a flat spring is adjustable. If you can figure out how to lock in the tension screw. You could have several tension screws and change them out to match the ammo. Say, an allen head for Winchester, a stainless one for federal and a blue one for everything

You would be better off having a good smith polish up the action and use a lighter return spring and set the main spring up to be 100% reliable. Smooth beats light every single time and that kit isn't going to smooth anything by itself.

Fishing lure made to sell to fisherman not catch fish.

My Smiths have "wore in" not out. No accessory parts needed.

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S&W Accumulator

Travis Strahan would do a coil spring conversion. A friend has a PPC gun he built, I will ask if he got the coil spring option.

Seeing that I prefer the trigger pull of all of my K-L-N-frames to the J-frames, why is this better?

Serious question.

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- Post No Bills -

and a good many love the pre coil spring I frames. I do.

A solution in search of a problem................

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S&W Accumulator

That likely has more to do with the more forgiving geometry of K-L-N-frames versus the J-frame than the coil versus leaf spring.

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Pickpocket

What about the geometry is more forgiving?

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protocalldesign.com

The larger frames allow for greater leverage when exerting force on the hammer. It isn't major, but I think it explains the generally lighter and smoother feeling pulls in them versus Js more so than leaf versus coil does.

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Pickpocket

OK, thanks!

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protocalldesign.com

Long my understanding and perceived experience. Always open to higher learning, of which I know you have much.

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Pickpocket

That's a very fine compliment coming from someone as knowledgeable as yourself. Thanks! As it happens, I just got the patent filed for my new hammer. Still a month or two out, I still have to finish a website, make engineering drawings, make jigs and fixtures, make a bunch of hammers, design printed materials, do pictures and videos, etc. plus working full time.

This hammer makes the trigger pull get lighter as the trigger goes back, kind of like a compound bow. My prototypes that are 100% DA on Federal primers are running about 6lb. at the beginning, down to 2lb. right before the hammer falls. Numbers are approximate because my measuring tools are not lab grade precision and every gun is different. Mine can also be dialed up to fire any primers. Stay tuned.

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protocalldesign.com

Delightful and intriguing -- please keep us posted.

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Pickpocket

I had to Google Astra revo and found a picture of the internals here: One Man's Surplus is Another Man's Project Gun - Part I | Top Rated Supplier of Firearm Reloading Equipment, Supplies, and Tools - Colt

I didn't have to google it myself - I have a Jovino Terminator in the safe with the adjustable spring mechanism. Pretty innovative and works just as intended. Like I said, a thicker ring that would allow for a six-step range of adjustments would have been a little better, but the current four-step adjustment range works quite well.

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Send lawyers, guns & money...

From the look of it, you must mill the inner walls of the grip frame
to accept the circular base of the spring. I'm not going to the extent
of milling the frame for any half *** ideas.

Too much non replaceable work for minimal if any improvement.

Ya, I don't see why they could not have made it just fit inside an existing frame cutout and lock in place with a replacement tension screw. It is interesting. The main advantage I see isn't the coil spring, it is the skeleton hammer. A light fast hammer is better than a heavy slow hammer. Lock time from trigger release to firing being shorter and with MxV² if the speed of the hammer is doubled the hammer can be 1/4 the wight and have the same energy. It it of course much easier for a spring to accelerate a light hammer than a heavy one. say the speed is 8 and the hammer is 8x8=64x6=384 while when doubling the speed 16x16=256 so the hammer weight could be just 1.5 as 258x1.5=384

Which is why cutting the spur off a hammer does not change its reliability as far as setting off primers.

The newer frames already have that circular cutout from the factory. I don't know why. The above information is correct. With the skeletonized hammer, a lighter spring of flat or coiled, can set off primers because it can get the light hammer up to speed faster than it can get a heavy hammer up to speed. There are upper and lower limiting factors on both hammer weight and spring pressure.

It follows that with lighter mainspring pressure, it will take less force on the trigger lever arm to cock and fire the gun in double action, and a lighter rebound spring to return the trigger and rebound the hammer, again reducing trigger pull weight.

Still, no one has ever addressed giving the trigger more leverage on the hammer, or giving the hammer more leverage on the mainspring since 1909. All the current revolver actions and aftermarket hammers are still based on this 112 year old patent, except for the Colt Python type action which never even made that improvement.

I think the holy grail of revolver smithing is a really good DA trigger, which has so far remained elusive. Everything else about modern revolvers is highly refined. It's long overdue for the trigger pull to be as good as the rest of the gun.

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protocalldesign.com

Cylinder and Slide made a bearing-equipped trigger a few years back, it felt smooth but was no lighter than stock in the gun I got to play with.

Korth has the smoothest DA trigger I’ve ever felt, but likely should at that price point.


I look forward to seeing the new PD trigger concept.

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- Post No Bills -

I have never taken a Ruger LCR apart to check out the operating mechanism, but isn't there a change from typical revolvers that increases "leverage" to give it the lighter DA trigger pull than a typical J frame has?

Larry

The Ruger LCR is still essentially the same as the 1909 design with some minor tweaks. It is probably an improvement (I don't have an LCR to play with), but different than mine. The reports I've read are saying they got a bit lighter, but mostly smoother. Those are 2 different attributes, although most people can't seem to distinguish smooth from light. They will say a light action is smooth, but can't discern the lightness aspect. Longtime revo shooters will know immediately.

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