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K frame tuning

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They have been able to achieve a surface finish on the DW parts that no one else has duplicated yet.
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I saw a (one, 1.0) Colt Trooper Mk III with a very nice action that would probably have responded very well to a little polishing and softer springs. It had nickel plated hammer and trigger in a blue gun. I figure the plating evened out the surface texture of the powder metal parts used in those guns.
 
'Tuner, much of my initial playing around was geared towards just getting a lighter pull. But as you say I've also realized that lighter isn't any better if it's not smooth. Hence my tinkering with a rebound block spring which uses a lighter guage wire with more turns than even the lightest Wolff rebound spring. The results with the 17 have been very good so far. But, and I never thought I'd say this, it's almost too easy to pull. This may well have something to do with the pivot and arc geometry mentioned by Old Fuff. In fact I'm almost certain that it does. The issue is that it gets almost too easy and fast at the last little bit of the DA pull.

Oh, and for all this the SA pull is truly devine with this light a rebound spring. Almost sinful in fact... :D But as I also shoot the gun in some speed related matches where DA is the name of the game I'm more than willing to "split the difference" between my last home made rebound spring and the lightest Wolff spring and hopefully even up the pull so that the spring pressure will build in concert with the greater leverage in the action's geometry so that the trigger pull evens out for the whole DA stroke.

I'm glad you mentioned about your preference for an even pull over anything else. It made me realize what it was that I somewhat disliked about my last version of my trigger job.
 
BC...When considering a spring change, many misinformed people will clip coils off an existing spring. That...IMO...is a mistake. A long, smaller diameter/weaker spring is better than a short, stiff one...so your reasoning is correct.

In the days before Wolff marketed different rebound springs, the practice by revolver smiths who understood this was to slip a sized rod into the spring and "roll" it on a belt sander to reduce its wire diameter. Not the ideal solution, but better than clipping coils.
 
Old Fuff, That ain't my gun! mumblemumblemumble
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My mistake... :eek:

Early on you mentioned a DW model 15, so I jumped to the wrong conclusion.

I think the picture still illustrated my point though.
 
Red Cent

I have been enjoying the discussion on this thread.

You do realize the outstanding caliber of advice that you are getting?

John (tuner), the Fuffster, Mr Boreland and Jim Watson are just some of the folks that I remember that have chimed in.

These are guys are damned smart!
 
Before the Wolff springs, folks like me used to lighten the S&W mainsprings by grinding the sides, not the flat. Keep the spring cool by dipping in water after each pass on the wheel. Works quite well, but you have to know when to stop. Don't grind the flat side of the spring and don't loosen or cut the strain screw.

----------

"Polishing doesn't remove metal." Coulda fooled me.

Jim
 
very appreciative
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I thought u were but these guys are world class.

While reading your thread I was once again reminded of the brilliance on these pages and was appreciative. Mentioning it to you was really just an excuse to post it.

Gotta love it!!!
 
1911tuner said:
BC...When considering a spring change, many misinformed people will clip coils off an existing spring. That...IMO...is a mistake. A long, smaller diameter/weaker spring is better than a short, stiff one...so your reasoning is correct.

In the days before Wolff marketed different rebound springs, the practice by revolver smiths who understood this was to slip a sized rod into the spring and "roll" it on a belt sander to reduce its wire diameter. Not the ideal solution, but better than clipping coils.
Click to expand...

Jim Keenan said:
Before the Wolff springs, folks like me used to lighten the S&W mainsprings by grinding the sides, not the flat. Keep the spring cool by dipping in water after each pass on the wheel. Works quite well, but you have to know when to stop. Don't grind the flat side of the spring and don't loosen or cut the strain screw.
Click to expand...

Interesting that you both posted information that I've used already. It tells me that I'm on the right track by using a smaller guage wire with a longer free length on the rebound spring so that the pressure build is more even over the entire travel. And that my grinding down the stock spring in lieu of the Wolff spring wasn't an entirely bad option.

Jim, my last main spring mod was on my 17 and involved not narrowing the width but reducing the spring force by grinding the back side so the spring took on a flatten'ed "D" shape with the arc on the rear face of the spring. I didn't want to reduce the width as that provides some side to side stability. But I didn't want to just make it thinner either. So far the "D" shaping seems to be working.

It'll be a few months before I can play more with this aspect as I'm in the middle of new house renos to build my shop areas. But I thank you both for the insights.
 
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If you choose to grind the sides of a spring (or the back) make sure to polish out any of the grinding marks. Such marks, if left, act as weak spots and fatigue causing the spring to break or fail.
 
BC...Yep, you are. I didn't realize you'd already posted it. Sometimes I don't have time to read all posts in a thread. Well...Most of the time, I don't. So many dogs. So little time. :D

A point that I've tried to make when addressing springs, and the practice of changing them around without considering all the implications is that some very smart people spent a lot of time working out the correct rates and loads. Yes, they generally do overspring the guns a little in order to provide some wiggle room...so that as they start to get tired, they still provide enough oomph to keep the gun working. Using a lighter spring narrows that window, so be prepared to replace it. In other words...have a spare.
"Two is one and one is none" is a good rule to follow.
 
All of a sudden I am hesitant to ask a question. You old experienced guys cut a young 69 year old some slack,OK?

Bending appeals to me. I guess you guys are cold forming the springs. The springs must have a high brinell number and that would suggest they would crack. Apparently, that is not the case.
If that seems to give me pause, then you turn to the strain screw. There would not be anything done to the spring.
Examining the results of each one at a time suggests that bending would offer the geometry desired if you do not have any trepidations regarding the spring.
Most Smiths in the world reside, for most of their life, in a neat place, therefore, nothing can be ascertained from the strain screw. The ones used in competition loosen (obviously) and mushroom. Is the mushrooming the result of cutting the strain screw? It would not seem logical that the bent spring would increase the stress on the screw.
 
Jim Keenan, early this century (got a ring to it) cowboy shooters would take their 1873s and their M97s and "hour glass" the springs. I have a couple of 1873s that have fired thousands of rounds without a failure of an hourglassed spring. There is a tiny flat leaf spring on the loading gate that has the same round count and with no problems. The failure of the factory loading gate spring is somewhat common and I wounder if the mirror polish that the hourglass ones receive further their lifetime significantly.
 
Smith & Wesson leaf mainsprings are blanked out of annealed flat spring stock, formed, and then heat treated and tempered. If you lay a new one on a bench you will see that it's flat, and not bowed. If over time it is removed from the revolver it should retain most if not all of its "flatness."

When bend the spring (in a cold state) you apply a stress that exceeds its normal elastic limits. If the spring is over hardened it will likely crack and break. If it is on the soft side (which most often it is) it will bend, but after it's installed and bowed may take a set. This can result in eventual ignition problems which require a new spring. It depends on just how much the spring is bent, and where.

The only thing I can say for sure is that a cold formed (bent) spring won't give you any trouble until something important is going on. :uhoh:

Mainspring strain screws are sometimes too soft, and mushroom on the end. If you see this as a serious problem heat the end of the screw cherry-red, and then quench it in oil. If that doesn't work, replace the screw.

I will again emphasize that too much attention is paid to polishing lockwork and tweeking springs, at the expense of ignoring other factors that affect a double-action trigger pull. Note that unlike your pet single action revolvers it is the trigger, not the hammer (acting through the hand) that revolves the cylinder. What is most important is smoothness over weight-of-pull, and borderline ignition can bring you to grief.
 
An analogy of tuning the Smith would be in racing. The more exotic the tune, the more pit stops taken.
Isn't it obvious that the strain screw would be the most "safe" way to approach the trigger assuming that some polishing is done? While it may not be the choice of the majority, it may be a good place for me to start. I think I will buy the "reduced power mainspring" and go from there.
I do not want to end such an informative discussion. Some important questions were answered. I am sure there are folks on this site with the knowledge of what we speak and it is gratifying to read posts from experienced shooters that also know of what we speak.

Tuner, I need to bring some McDonald's coffee down and do a "show and tell". I realize Mac's coffee is weak compared to the "turbo" coffee.
 
Don't much abide with bending springs. That'll stress the steel beyond its limit, and make a weak point. Like stretching a spring beyond its elastic limit...like a magazine spring...to add some length to it. It works for a very short time, and then the spring collapses again, and you wind up with a shorter, weaker spring than if you'd left it alone.

Say when, RC. You bring the biscuits from Mickey's. I'll tend to the coffee.
 
Oh, yeah. Back to the strain screw thing.

It would be the simple, fast way for sure...but there's more to consider than having to take a few extra pit stops. The gun was designed to operate with a given arch in the mainspring. Trimming the strain screw makes the question of reliable/consistent ignition a concern...but that can usually be handled by using Federal primers. Misfires aren't the real boogeyman here, though. Hang fires are. In the heat of competition or an "Up to your Crotch in Crocodiles" moment...a misfire with a revolver is most often immediately followed by another yank on the trigger. If the round that misfired is actually a hangfire induced by a light strike...and it's now indexed away from the barrel...things could get real interesting in about 30 seconds...or less.
 
Then the answer mght be to practice with the radical mods a bunch and build up the spring strength and live with the polishing and dry firing.. Won't do away with the squib.
Amazingly, in cowboy shooting we run the pistol really fast, especially if we sliphammer. But I have never seen a "good" shooter fire the next round. Seems if our brain detects the problem in a nano second and stops us. Other times I have seen newbies blow out the first bullet in a rifle.
 
Easier to catch a squib in a revolver since recoil impetus is transferred instantly to the hand. Easy to miss it in autopistols, since the slide sometimes makes a full trip rearward and strips and chambers another round. The felt recoil in an auto comes from the spring pushing backward into the hand...and the bulk of it occurs when the slide impacts the frame. Since some squibs can cause the slide to cycle...the reduced recoil impulse is usually missed if the shooter is running it fast.
 
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