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S&W strain screws

Discussion in 'Handguns: Revolvers' started by Hawk, Jul 11, 2008.

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  1. Hawk

    Hawk Member

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    Is the strain screw used on S&W models with flat springs supposed to be an "adjustment screw"?

    I was under the impression it was supposed to be tightened down more or less like any other screw but I seem to be seeing more and more posts indicating that S&W's own performance center is filing the thing down and even Kuhnhausen makes reference to "carefully" trimming the thing or some such.

    I knew backing the thing off would reduce mainspring pressure but somehow had it associated with "shadetree" adjustments not held in high esteem by the same folks that would exhibit discomfort over inserting leather washers under Colt SAA mainsprings.

    So is strainscrew tweaking a "mainstream" thing endorsed by the likes of the S&W Performance Center and Kuhnhausen or something done but not much discussed in polite company?

    Those of us that inserted Brownell's reduced power mainsprings in 28-2s but didn't notice much difference are curious...
     
  2. Old Fuff

    Old Fuff Member

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    The purpose of the strain screw is to make it easy to remove the spring when that is necessary. In theory, it is not supposed to be used to adjust the spring's tension. To work correctly the spring is bowed to a certain curve, and changing that can lead to all kinds of trouble.

    On the other hand, all mainsprings are not created equal, so sometimes if the spring is "too stiff," a very small ammount on the end of the screw is trimmed. Experienced gunsmiths know how far works as opposed to "too far."

    The critical point is to maintain the right bow, and to also be sure that when the hammer is cocked, the back of the rebound slide doesn't touch the mainspring.

    I propose that you play a bit by backing the screw out, but no more the 1 1/2 turns, without trimming it. You can always trim it later. Doing nothing won't teach you anything. :cool:
     
  3. buttrap

    buttrap Member

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    I have backed the things off for shooting at the range at times. It will lower the pull a fair amount but as Fluff pointed out the bow factor is critical. Also as Fluff noted the trimming idea is the proper method so the screw wont back off and cause you to jam up from the spring hitting the frame. It does not take much trimming to get you in trouble too especialy with the older Smith that used a pointed screw tip vs the newer flat tips.

    I use the same method that Fluff advises and belive me its good advise. Last resort just get a spare screw and have fun.
     
  4. Standing Wolf

    Standing Wolf Member in memoriam

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    That darned Fuff doesn't leave too many nails bent over.

    Having a spare part before you start "fixing" things is a good idea. Yes, I had to learn that one the proverbial "hard way."
     
  5. Old Fuff

    Old Fuff Member

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    And you think the Old Fuff learned the easy way... :D
     
  6. def4pos8

    def4pos8 Member

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    DAMMIT BOY! I sure wish there were some way to share a few beers with Old Fuff!! Zen and the Art of Smith Maintenance. . . .;)
     
  7. Hawk

    Hawk Member

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    Well, it would appear a little goes a long ways.

    Around 1-1/2 turns it's closing in the "686 of light strikes". Left it at 1/2 turn which still launches a pencil like a mini Atlas-Agena and will try it that way. Meantime I'm kind of warming up to thing fully bottomed anyway. Even if it's only a range gun I would prefer it not start acting like the "686 of troubled ignition / nice trigger".

    There's room under the target grips to back it out a couple turns - I guess the reason tbe screw is trimmed is so the head can be flush with the front strap?

    FWIW, the "686 of troubled ignition" turns out to have the strain screw fully seated with no obvious filligree work on the spring - I'm guessing it's lighter than the Brownell's / Wolff "reduced power" main spring. I love used revolvers - it's like waking up in a new world every day - I've no clue where the 686's spring came from or what may have been done to it. I'll probably stick a Brownell's in there as the misfires have belatedly gotten on my nerves.

    Interesting stuff - thanks all.
     
  8. machinisttx

    machinisttx Member

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    IMO, you're going to see more trigger weight reduction by changing the trigger rebound spring than you will changing mainsprings. You also won't run the risk of light primer strikes.

    On all my fiddled with S&W's, I've done nothing more than change the rebound spring. Two of them have DA pulls at the 9 pound mark, with the single action on one of them coming in at 2.5 pounds, the other is DAO. The others I haven't put a scale on, so I can't comment on them other than saying they feel better now.

    It's possible that someone bent the original mainspring to reduce the trigger pull.
     
  9. buttrap

    buttrap Member

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    The trigger rebound spring is the real key to get a smith slicked up but they are a pain in the ass to deal with. 40 years of tearing the things to all hell I still have a ashtray full of after market rebound springs and most of the rest of of a tume will go fine not dealing with that issue.
     
  10. Hawk

    Hawk Member

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    The Brownell's reduced power spring "kit" came with 3 rebound sllide springs - I just grabbed the middle one, I think 14 pounds.

    Roger that with the PITA to deal with. Although the cylinder stop spring was no slouch itself - I was starting to relate to those that view engineering changes as never good - most specifically, the loss of the 4th screw.

    Guess I'll try the 13 pounder next time I'm in there.
     
  11. texagun

    texagun Member

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    I have played with the strain screw on several S&W's over the years and never noticed that much of a difference in them. And I never felt comfortable leaving them backed out, so all of mine are screwed fully in for maximum reliability. I think the stock S&W triggers are pretty much excellent right out of the box so I leave them that way. I've been reading Ed McGivern's classic, Fast and Fancy Revolver Shooting, and it's interesting that he repeatedly says all of his shooting has been with bone-stock S&W revolvers with no tuning at all. By the way, Old Fuff's explanation is the best I've ever read. That guy knows his stuff.
     
  12. Old Fuff

    Old Fuff Member

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    You can reduce the rebound slide (trigger) spring a little, but it isn't as good an answer as some think. The spring not only controls the trigger's return forward, but also rebounds (backs off) the hammer against the remaining mainspring tension, and pushes the cylinder stop forward as the hammer and trigger return forward to battery.

    All of these springs work together and are balanced against each other. Making too much of a good thing by trimming or replacing the rebound slide spring and ignoring the others can leave you short-stroking the trigger during rapid double-action firing.

    It should be understood that factory springs are on the heavy side for good reason – especially on models such as the 28 Highway Patrolman. They are (or were) intended to be used in police service where it was ABSOLUTELY NECESSARY that when called on the revolver would… without question… go bang! No excuses being necessary or acceptable. When the revolver is used for other purposes some reduction is acceptable, but what you are really doing is scaling back the reliability margin.

    If one wants to discover the very best in revolver double-action trigger pulls they need to purchase one made between the two world wars. These had no compromises in quality, and Smith’s famous “long action.” The spring tensions can be reduced a bit without affecting reliability because they ere designed to fire primers that were less sensitive then those we have today. The trigger pull is smooth, and without any feeling of the parts interacting with each other. While the models built on the N-frame are usually very expensive, the K-frame Military & Police model can often be found in like-new condition for under $400.00, and sometimes well under that for those with a little bit of finish wear.

    Last but not least, Hawk needs to buy yet another book: Fast and Fancy Revolver Shooting by Ed. McGivern. It’s an old book, first published during the early 1940’s. Original copies sell for well over $100.00, but reprints are far less expensive. Check out amazon.com This book by the way is about shooting, not gunsmithing, and very enlightening about what can be done with a first-class double action revolver.
     
  13. Old Fuff

    Old Fuff Member

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    Oh nuts... Texagun beat me to the draw. But I second his recommendations... :)

    And I'll point out the obvious. McGivern's revolvers were all pre-World War Two production, but with him I'm not sure that would have made any difference. Also just after that war, for a short period, S&W made some so-called transitional revolvers that had the pre-war long action, with the post-war positive hammer block safety. These may be the best of the breed. One of the Old Fuff’s top favorites is “Old Junker,” - the name is affectionate – that is a 4” Military & Police that can cause Python owners to swoon after trying the trigger pull. Additional details as to which models will be found in Standard Catalog of Smith & Wesson, which I’ll mention yet again.
     
  14. Hawk

    Hawk Member

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    The Standard Catalog has arrived. I had 'em toss in a copy of "Images of America" as I'm a sucker for Amazon's "how about a package deal" pitches.

    I'm sure the McGivern thing is impressive but I doubt I'll ever get very far even with slow and not so fancy. The 28-2 had my index finger bleeding such that I had to wait until it crusted over. It's getting a tad tougher and right now looks like shed snake skin. That was something shooting tuned mutant 1911s didn't prepare me for. ;)

    Waiting for one's bleeding trigger finger to scab over is one of those minor hiccups in my new revolver relationship. One takes the bad with the good. But I'm at a stage in life where I seriously doubt I will ever be able to utter "double action" and "accuracy" in the same sentence. It's not that big a loss - that's why they put that single action notch in there. If I wanted to shoot bullseye employing a trigger that resembles gymnasium equipment I should have started much earlier.

    Even though I view wheelguns as a hobby, I prefer reliabiltiy. The lighter Brownell's main spring doesn't compromise hits but I'll probably bottom the strain screw and learn to live with it "as is". Which isn't really terrible, after all.
     
  15. Jim K

    Jim K Member

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    Just FWIW, I have a Model 28 and at one time I shot it a lot, mostly DA, without losing any blood or having any scab. I did a trigger job on it later and it is even better, but the original spring gave no problems.

    Jim
     
  16. rcmodel

    rcmodel Member in memoriam

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    I just finished repairing a .44 Special Triple-Lock this morning for a friend.

    He bought it last week and was complaining of very hard single-action cocking.
    As the hammer almost reached full cock, it became very hard to pull back any further.
    And the single-action trigger pull was very heavy.

    One and 1/2 turns, to fully tighten the strain screw, fixed it so it cocked easily, and lightened the SA pull by at least 2 pounds.

    In short, the old Triple-Lock again works perfectly, just as it was made.

    The hooks on the top of the mainspring were contacting the inside of the hammer curve cut because the spring wasn't bowed far enough to clear it.

    I highly recommend leaving the strain screw fully tightened unless you understand all the ramifications of loosening it slightly.

    rcmodel
     
  17. Hawk

    Hawk Member

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    It's my wild guess that, if my experiences with revolvers were typical, you all would be in the semi-auto forum having given up the alternative as a bad job decades ago.

    FWIW, my 57s aren't as bad. The 28 seemed heavier but I haven't built my "bucket trigger gauge" yet so the degree is unknown. The trigger seems "sharper" as well. Narrower than the 57s but subjectively sharper serrations. Fuff advised on how to get rid of sharpness but I thought I'd try it on its own terms first. If I grow a calous, I'll probably leave it that way.

    'Couse it could be that revolver folks just have a calous they got so long ago they've forgotten it's there. :D
     
  18. Old Fuff

    Old Fuff Member

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    I wouldn't want Hawk to find this out, so don't anybody tell him... :D

    In S&W revolvers, the K, L and N frame use different hammers but the same trigger. I believe that both Brownells (www.brownells.com) and Numrich (www.e-gunparts.com) still have pre-MIM triggers that have a smooth face.

    Now I don't worry about Hawk because he's expendable, but I am concerned about his finger. Clearly he is mistreating it. So maybe what he needs to do is replace the trigger that is abusing his finger and replace it with one that won’t. There is a strong likelihood that the second trigger will work without fitting, or with only very minor work.

    Remember mum's the word... don't anybody let the cat out of the bag. :D
     
  19. Hawk

    Hawk Member

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    Smooth triggers? Yum.

    You nearly succeeded it keeping it a secret - I was headed for Charlotte sans laptop (old fashioned traveler, I guess) and the thread would've scooted off the bottom of page 1 where I likely would have missed it.

    But my connection in Atlanta was blown so here I sit unpacking stuff at the office, drinking bourbon and coke and finding out about smooth triggers.

    If nothing else, revolvers seem to have improved my karma some - usually, blown connections have no redeeming qualities whatsoever but this time I learned something so I guess this is an exception.

    One question though, and yeah it's serious - indulge me if you will - are you saying DA revolver shooters DON'T develop a calous?
     
  20. Old Fuff

    Old Fuff Member

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    I can't say that none do, but I don't see why that would be the case if the trigger was smooth. The only handgun that left me with calluses was John Browning's favorite .45 pistol, and that was on the web of my thumb.

    A rough or sharply serrated trigger will abrade the skin, and I can see how a callus could result from that. My mentor when it came to double-action revolver shooting was Bill Jordan, and he strongly preferred a smooth trigger face. I have tender skin, and as a result I usually either dull or remove serrations except on a few collectables.

    Take a strip of electrical tape and put over the face of the trigger on your model 28. I think this will soon tell you if a more permanent alteration should be made.
     
  21. Hawk

    Hawk Member

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    Oops. I was mistaken. The strain screw on the "686 of troubled ignition" has been molested. I didn't notice the thing indexes on the head until I went to put in a stouter spring tonight.

    Brownells doesn't catalog the screw anymore but S&W shows the things - guess I'm going to have to find something to go with it - I suspect 1.58 is under their minimum.

    Another oddball observation: the 686 of troubled ignition is only the second S&W sideplate I've removed. The innards of the 686-no-dash-no-"M" are from a different planet than the 28-2. The 686 makes the 28-2 look like 30 miles of bad road by comparison. It wouldn't be much of a stretch to say the 686 looks like watch parts compared to the nasty stuff inside the 28-2.

    One of the several issues with being a noob is that I'm not certain which is the "real" S&W - I'm betting the 686 as bubba wouldn't introduce tool marks where none had been (on the 28) previously. I suppose it's possible the 686 was cleaned up post factory but that doesn't seem real likely. The 686 has restored my faith. I wonder if the difference could be carbon vs stainless steel? Hopefully not. The most obvious difference is the inside of the frame - the 28-2 was rough enough that stoning the rebound slide couldn't produce much in the way of results as it's still riding over an area of the frame that looks like a train wreck and it wasn't real obvious how one would get into that area to clean it up. That and I wasn't sure it was unusual at the time. Now that I've seen the 686 I'm inclined to believe the 28-2 is a "Monday gun". That has its advantages - makes it a good S&W to practice on - not too many ways I could make it worse.
     
  22. machinisttx

    machinisttx Member

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    The older S&W's I've popped open were all pretty rough looking inside. The newer ones, not so much. Back in the day, all they had was manual machines and I don't even want to think about how many setups it would have required to produce a complete frame(keep in mind that I am a machinist). That added up to a lot of time, and as a consequence they were more worried about production speed than surface finish/roughness. Modern CNC machining centers eliminate the need for all those setups, as well as all the time spent moving the workpiece(frame) from place to place. All of that time formerly used for shuffling them around now gets used in slower feed rates that produce better surface finishes.

    What I've done on the rough surfaces such as the one the rebound slide rides on, is to take 600 grit sandpaper and wrap it around a flat, narrow object. You don't need to polish all of the tool marks out, but 75% cleanup is a good goal if it won't remove too much metal. Also stone the bottom of the rebound slide, preferably finishing with an Arkansas stone.

    My 28-2 is well used, but IMO it probably has the best feeling trigger and action of any of my Smiths. It's not the lightest, but damn it's smooth like butter! As good as it is, I haven't seen any reason to try to improve it. My other, less used, Smiths often need a little here or there. A recently purchased(and nearly unused) M31-1 has an absolutely terrible trigger. Drag, creep, and too much weight. Dry firing and a little shooting will probably take care of the drag and creep---it does wonders.
     
  23. Hawk

    Hawk Member

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    They're like snowflakes - each is unique even within the same model number and "dash" number.

    I don't have a lot to judge by but my 28-2 had the gnarliest trigger of any of my S&Ws including a 27-2, couple of 57s, couple of 686s, 640, couple of 66s and a "new" 40.

    If I'm reading the Standard Catalog right, the 686 was only separated from the 28-2 by three years - looks more like 25 years using one's eyeballs. Whether the other 1970s examples turn out looking as rough as the 28-2 they've already lost any chance of "feeling" as rough.

    The 28-2 really was quite special - not in a good way.
     
  24. Hawk

    Hawk Member

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    This might be a good time to paste a post I found on another forum dating from 2002. There are a number of posts I've saved from Fuff and Tuner, this one is from Dfariswheel.

    I keep it as it calms me when I read that somebody else's 28 is smooth while mine is less than stellar. If even makes me feel better when I remember my getting a Python that blew chunks while everybody else was singing internet hosannas as though they were all crafted by angels with golden hammers and silver forges.

    [gump] A revolver is like a box of chocolates... [/gump]

    Anyhow, here 'tis:



    One more time:
    You cannot judge a gun based on just the year it was made. Guns aren't wine.

    Each individual gun must be judged on it's own merits.
    I've seen recent Colt and S&W guns that are made in "bad times" that are some of the finest quality guns I've ever seen.

    I've seen a Colt Officer's Model from the 1930's when quality was supposed to be the absolute top of the mountain, that was a mess. Bad blue job, bad action, misfit sideplate, badly out of time, it should never have left the plant, especially then.

    I've seen a pre-war REGISTERED S&W .357 Magnum, supposedly the finest quality gun S&W ever made, BRAND NEW IN THE BOX, that looked like something a shade tree mechanic put together. Barrel not indexed properly so the sight was off to the right, there was NO barrel-cylinder gap, cylinder crane didn't lock up properly and you could actually hear the cylinder clunking if you shook the gun sideways, the hammer would "push off", and a blue job with scratches, ripples, and dished-out areas.
    The original owner kept it as a, then rare, factory curiosity.

    The point is, people who say "Oh, I've never buy a 1990's Colt or Smith, their not any good", is passing by some good quality guns.

    The current crop of guns is not up to the old standards because the OLD PEOPLE are gone. With all the strikes, layoffs, corporate downsizing, and more layoffs, the old workers are all gone.

    The people who knew exactly how to make high quality guns, and took pride in their workmanship have been replaced by off-the-street employees who know little about guns, and haven't the experience and skills.

    A lot of this I blame on the Harvard-Yale-Wharton MBA grads that are running, and ruining companies today. They are taught to watch the money. Ignore the product, ignore the production floor, ignore the workers, and ignore quality. Manage the money and everything will be fine.

    These people have the same attitude toward workers. The theory is: workers are as interchangeable as screws and bolts. It doesn't matter if you're making paper, jet aircraft, cars, plastic, or guns, the same people will do fine.

    There is a difference in "gun people". They have the natural talent base that allows them to develop high order skills, and the pride in workmanship. people like this make good guns, in spite of the company. "Interchangeable" people will make bad guns in spite of the company.

    Bottom line: Judge a gun on it's own merits, not when it was made. You might be pleasantly surprised.

    November 2002
    Dfariswheel
     
  25. Deanimator

    Deanimator Member

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    A few years ago, I bought a police surplus 3" S&W Model 65. When I got it, there were a LOT of failures to fire. I don't mess with the guts of revolvers, so I gave it to the guy who works on all of my handguns to look at. He took the grips off and looked at the strain screw, which was tight. We stood there and scratched our heads for a couple of minutes before I said, "I wonder if the cop who had it before 'fixed' the strain screw?" My smith hadn't brought any strain screws with him to the range that night. He took the gun home and changed strain screws. The next week, I shot it and haven't had a misfire since.
     
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