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Revolver cylinder tolerances

JasonMPDJasonMPD Senior MemberPosts: 6,557 Senior Member
How tight should a cylinder lock up when the hammer is at full cock?

1.) Motionless?
2.) .005-.015 wobble?
3.) .015-.030 wobble?

Is more acceptable? I ask because my Model 69 44 Magnum is probably in the option #2-ish range. Probably more on the .015 +/- a few thou.

If the cylinder motion is unsatisfactory, what's the fix?


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“There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” – Will Rogers

Replies

  • NNNN Senior Member Posts: 24,962 Senior Member
    That is an interesting question, they all wiggle a little if you try hard enough
    how does someone measure that issue?

    What I have heard before is if it isn't shaving lead it is ok.

    I wait for a gunsmith reply.
  • earlyearly Senior Member Posts: 4,950 Senior Member
    Never measured any. Some are tighter than others. I can't tell any difference in performance from tight or wobble.

    I'd be real sceptical of a problem with that 69.
    My thoughts are generally clear. My typing, not so much.
  • NNNN Senior Member Posts: 24,962 Senior Member
    Do you mean wobble without trying to wiggle it?
  • breamfisherbreamfisher Senior Member Posts: 13,692 Senior Member
    If you're talking wobble side-to-side when viewed from the muzzle or the hammer, some is normal for most everything. Manufacturers tend to do this to allow the bullet to self-align with the forcing cone when it fires. As far as tolerances go, I have no clue.

    Note: to test lockup for almost every revolver, do it with the hammer at full-cock. The only exception would be with the Colt Python and Detective Special, and similar actions. For those you test lockup with the trigger pulled.
    Overkill is underrated.
  • JasonMPDJasonMPD Senior Member Posts: 6,557 Senior Member
    NN wrote: »
    Do you mean wobble without trying to wiggle it?


    I should clarify it's ROTATIONAL movement of the cylinder on the center pin, not lateral movement from the yoke. That's locked up solid.

    The cylinder rotates probably .015+/- a few clockwise and counter-clockwise of top dead center.

    I don't think it's shaving lead; all fowling seems normal. I'm not speculating a warranty issue with the gun. I became curious just handling it and observing some of the finer mechanical movements.

    Another forum stated Taurus tech support stated that 1/32" (about 0.0313") was acceptable for their guns. And I'd suppose if a Taurus can survive that misalignment for thousands of rounds a quality SW revolver sure will.

    As for accuracy I'm less experienced with wheel guns so it shoots better than I can. No reloading experiments yet.


    Sent from my iPhone using Tapatalk
    “There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” – Will Rogers
  • JasonMPDJasonMPD Senior Member Posts: 6,557 Senior Member
    And I found this dandy nomenclature diagram in my fit Google searches.

    a245188379760a65e144456dec08ed1d.jpg


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    “There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” – Will Rogers
  • NNNN Senior Member Posts: 24,962 Senior Member
    I quess it depends on how tight a fit there is with the bolt and the slots in the cylinder.

    I just checked a SP 101 and not much probably the low side of your example #2;

    Then a Blackhawk, much more rotation available and looser fit of the bolt and those slots.

    Both shoot ok.
  • mitdr774mitdr774 Member Posts: 1,582 Senior Member
    My 629 has always had some rotational slop to it. I never had any issues with .44 Mag loads. On the last outing I was shooting some .44 Special with plated bullets and a slight issue developed. After being pelted with some debris (and a small piece of lead deflecting off the lane divider and depositing itself under the skin of my cheek) I checked for issues. While I can not find any alignment issues I did notice some lead build up directly above the face of the forcing cone. I am not sure if this is a bullet/case issue or a timing issue. Im guessing not timing due to the even spread across the bottom of the top strap.
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    Are you talking about end-shake?

    Gunsmithing - How to Correct Excess Cylinder Endshake on a Smith and Wesson (S&W) Revolver

    The gap between the rear of the forcing cone and the cylinder face?

    https://www.youtube.com/watch?v=HySO2lrO7UA

    https://www.youtube.com/watch?v=95xjizDOrcc
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    Oh and don't do a 'Jack Webb' movie/TV trick and flick the cylinder closed on a DA revolver.....very bad for it.........use your fingers/thunb and push it closed.
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • tennmiketennmike Senior Member Posts: 27,457 Senior Member
    Big Chief wrote: »
    Oh and don't do a 'Jack Webb' movie/TV trick and flick the cylinder closed on a DA revolver.....very bad for it.........use your fingers/thunb and push it closed.

    Yeah. Replacing a bent crane ain't cheap! :silly:
      I refuse to answer that question on the grounds that I don't know the answer”
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  • LinefinderLinefinder Moderator Posts: 7,494 Senior Member
    tennmike wrote: »
    Yeah. Replacing a bent crane ain't cheap! :silly:

    If done correctly, it's cheaper to buy a new gus.

    Mike
    "Walking away seems to be a lost art form."
    N454casull
  • jaywaptijaywapti Senior Member Posts: 4,995 Senior Member
    I just checked 4 of mine, 2 old 3 screw Blackhawks a .41 & a .44 both with lots of rounds, and 2 new Charter arms, both less than 50 rounds, a .357 & a .44 spc., all 4 had a little rotational movement, all slightly less at full cock.

    JAY
    THE DEFINITION OF GUN CONTROL IS HITTING THE TARGET WITH YOUR FIRST SHOT
  • JasonMPDJasonMPD Senior Member Posts: 6,557 Senior Member
    Big Chief wrote: »
    Oh and don't do a 'Jack Webb' movie/TV trick and flick the cylinder closed on a DA revolver.....very bad for it.........use your fingers/thunb and push it closed.


    Yep I don't do that show-off crap. I close it properly.


    Sent from my iPhone using Tapatalk
    “There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” – Will Rogers
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    JasonMPD wrote: »
    Yep I don't do that show-off crap. I close it properly.


    Sent from my iPhone using Tapatalk

    Good.

    Lot of folks don't know that, especially those who use mostly semis exclusively and are letting the slides/bolt fly forward with a release or 'Slingshoting' them or seating a magazine with force.
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • BigslugBigslug Senior Member Posts: 8,763 Senior Member
    The only thing I've seen that's totally motionless is a Freedom Arms. On a more normal tolerance range gun, that little bit of wiggle will allow the bullet to center up in the forcing cone as it passes out of the cylinder. Not a bad thing at all.
    WWJMBD?

    "Nothing is safe from stupid." - Zee
  • LinefinderLinefinder Moderator Posts: 7,494 Senior Member
    One thing I've noticed with my 686..

    With the hammer down, there's a bit more rotational movement than you'd think acceptable. With the hammer fully back, this movement is cut in half.

    But, if I lower the hammer slowly (finger on trigger, thumb on hammer), the cylinder is tighter than a drum.

    I'm thinking while the hammer is falling is the important thing.

    Mike
    "Walking away seems to be a lost art form."
    N454casull
  • LinefinderLinefinder Moderator Posts: 7,494 Senior Member
    Another thing I've learned in becoming a machinist / toolmaker.

    Everything has a tolerance. It's physically impossible to have a 1:1 fit. A .061" gage pin will not fit into a .061" hole. Deltronic pins, sized at .0001" increments are used when tolerances are"tight", but even then, temp of the part, temp of the pin, has to be taken into account and that's a tough thing to gauge in and of itself.

    Mike
    "Walking away seems to be a lost art form."
    N454casull
  • Gene LGene L Senior Member Posts: 12,347 Senior Member
    Big Chief wrote: »
    Are you talking about end-shake?

    Gunsmithing - How to Correct Excess Cylinder Endshake on a Smith and Wesson (S&W) Revolver

    The gap between the rear of the forcing cone and the cylinder face?

    https://www.youtube.com/watch?v=HySO2lrO7UA

    https://www.youtube.com/watch?v=95xjizDOrcc

    If you have endshake on a S&W revolver, it's easy to stretch the crane. You can buy a crane stretcher from Brownell's or you can make your own, which is what I did. A crane stretcher is almost identical to a pipe cutter, except the wheels are dull. I had a Model 28 that had unacceptable end shake and so I bought a cheap tubing cutter and dulled the wheels with a round file.

    Cost about $4 or so. Took off the crane and turned it on the tubing cutter (dulled, of course) and after a few turns, far less than I expected, it stretched the crane and eliminated end shake. If you over-stretch it slightly, you can file the excess off a bit. Not much, though.

    I tried to explain this to another person who couldn't understand the concept. It's like taking a long balloon inflated and squeezing it in the middle. The balloon will be slightly longer.
    Concealed carry is for protection, open carry is for attention.
  • LinefinderLinefinder Moderator Posts: 7,494 Senior Member
    cpj wrote: »
    I have an idea on how to set up a revolver to meausre it accurately. Or is that precisely?
    Anyway, I may do just that if I get off work at a decent time tonight.

    Let me know how it goes. That would be an interesting thing to learn.

    Mike
    "Walking away seems to be a lost art form."
    N454casull
  • LinefinderLinefinder Moderator Posts: 7,494 Senior Member
    cpj wrote: »
    I'll post a video. You think about how you would do it. Dont say till after I post the video.
    If it works how I think it will work, its bonehead simple to do. Of course without any tolerance numbers to see if it's within spec, it'll be perfect every time. Win/Win! !

    Fixed.

    Mike
    "Walking away seems to be a lost art form."
    N454casull
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    Gene L wrote: »
    If you have endshake on a S&W revolver, it's easy to stretch the crane. You can buy a crane stretcher from Brownell's or you can make your own, which is what I did. A crane stretcher is almost identical to a pipe cutter, except the wheels are dull. I had a Model 28 that had unacceptable end shake and so I bought a cheap tubing cutter and dulled the wheels with a round file.

    Cost about $4 or so. Took off the crane and turned it on the tubing cutter (dulled, of course) and after a few turns, far less than I expected, it stretched the crane and eliminated end shake. If you over-stretch it slightly, you can file the excess off a bit. Not much, though.

    I tried to explain this to another person who couldn't understand the concept. It's like taking a long balloon inflated and squeezing it in the middle. The balloon will be slightly longer.

    Wouldn't it mo easy just to pop in a couple them washers they sell like on that Midway video?
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • LinefinderLinefinder Moderator Posts: 7,494 Senior Member
    The tough part is how much time do you want to devote to the project.

    Working with existing things is much more difficult than starting from scratch.

    If I'm building from scratch and the speced tolerance is .005", I'm going to produce a part within .0015".

    I have no idea, however, what the previous guys tolerance was, nor his work ethic. So, yo measure EVERYTHING, plumb, level, square, parallel, flatness, etc. ad infinautim. And it usually sucks.

    Oh....and if your measuring devices are calibrated by an independent lab every three months and his stuff has been dropped on the floor three times in the last six months.....

    Well.....you see where I'm going......LOL.

    Mike
    "Walking away seems to be a lost art form."
    N454casull
  • Gene LGene L Senior Member Posts: 12,347 Senior Member
    Big Chief wrote: »
    Wouldn't it mo easy just to pop in a couple them washers they sell like on that Midway video?

    Maybe. I'll take my solution over washers. I don't know, but it's probably cheaper and works just fine.
    Concealed carry is for protection, open carry is for attention.
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