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Problem with Centennial M 40

Discussion in 'Handguns: Revolvers' started by rainbowbob, Jul 13, 2010.

  1. rainbowbob

    rainbowbob Well-Known Member

    I purchased a beautiful S&W Model 40. My intent was to make my everyday pocket carry. While practicing reloads with a speedloader at the range, I discovered that when the cylinder was positioned in a particular spot, a case would hang up on the cylinder stop and I was unable to eject the spent ones.

    I compared the cylinder stop (at least I think that's what it's called) with my other J frames and K frames. This one is shaped slightly different and protrudes a little further - just enough to hang up.

    I'm no gun smith, and I don't want to just go after it with a grinder.

    Have any of you very knowledgeable revolver shooters ever encountered this problem?

    Do you so suppose sending it to S&W is the best idea? I may have them slick up the action and do a once-over while I'm at it.
  2. rcmodel

    rcmodel Member in memoriam

    All J-Frames since the old flat-latch went away have had some minor cylinder clearance problems with speed-loaders and ejection.
    They can only open so far away from the frame and cylinder latch due to the small size of the frame & crane.
    The trick is to roll the cylinder slightly with your right hand holding the gun, or left fingers while punching the ejector rod.

    Same with speed-loaders. Roll the cylinder a little while lining up the new ammo with the holes and the speed-loader will slip on by the latch.

    You also need to always keep the muzzle pointing skyward when ejecting with any revolver.

  3. rainbowbob

    rainbowbob Well-Known Member

    Thanks for your response rc. I think perhaps you misunderstand my problem...probably because I'm not describing it very well. So I'll give it another try.

    The cylinder latch isn't the problem (although I know it can get in the way of a speedloader).

    The problem is the small protrusion at the bottom of the frame that prevents the cylinder from dropping off the yoke.

    I have four S&W revolvers (2 J frames and 2 K frames). Only on the M 40 does the protrusion I am talking about hang up one of the cases, thereby preventing the ejector from moving. This protrusion (that I'm calling the cylinder stop, perhaps incorrectly) sticks out further than it does on of my other revolvers.
  4. rcmodel

    rcmodel Member in memoriam

    Is this a new production Model 40?
    Or an old original one?

    The older guns used a separate steel frame lug (cylinder stop) pressed in from inside the frame and hand fitted to the cylinder length in question.

    The new guns have the frame lug machined as part of the frame, and are certainly not like the older ones.

    Still, I can't quite imagine it sticking out far enough to interfere with ejection, unless they machined it too deep and the cylinder is going down in it too far brfore stopping.

    I just went and looked at my older 36 & 49 and both frame lugs have a taper clearance cut to miss the rims of the cases.

  5. rainbowbob

    rainbowbob Well-Known Member

    It's an older (1970s) model. If the cylinder happens to land just right when opened (not a rare event) the case lip of one of the spent rounds is pushed against the cylinder stop.
  6. rcmodel

    rcmodel Member in memoriam

    Well, again, turning the cylinder slightly with the fingers of the hand holding the gun vertical while hitting the ejector rod cures a multitude of problems.

  7. rainbowbob

    rainbowbob Well-Known Member

    That is true, although my preference would be to have to think about it or get hung up for even a moment.

    Do you - or anyone - have any experience with an action job by the factory? As i said, I'm thinking about doing that, and would ask them to shave the cylinder stop while they had it.
  8. Old Fuff

    Old Fuff Well-Known Member

    I suspect that your model 40 is one of those that has a cylinder lug (you called it a "stop") that's staked in the sideplate. On rare occasions they can become loose and back out enough to cause the situation you described. They can re-staked, but I recommend the factory do it because a mistake can leave you with a warped or bent sideplate - which isn't good.

    It is also possible that it wasn't correctly fitted in the first place, in which case S&W will usually fix it on their dime, including shipping.

    However keep in mind that when the early model 40;s were made during the late 1950's and early/mid '60's rapid reloading using speed loaders was not the common practice it is now, so such things were not taken into condideration.

    In any case, if you return the revolver to Smith & Wesson, any and all of the ills it now has, and others that might be detected, would be taken care of.
  9. rainbowbob

    rainbowbob Well-Known Member

    That's what I'll do...thanks. I wonder if they can lighten up the DA trigger a little?
  10. bannockburn

    bannockburn Well-Known Member


    I don't know if they're still being made, but for many years I used Bianchi Speed Strips for my concealed carry reloads. Basically they consisted of a flat metal strip, covered in a pliable rubber material. Flat and easy to carry, I found them to be pretty useful, provided of course you practiced enough with them. They were a decent altenative to a cylindrical speedloader because I also had problems like you described with some of my J frame revolvers.
  11. Old Fuff

    Old Fuff Well-Known Member

    Only at the expence of reliability. The problem is that the hammer and trigger pivot pins (called "studs") are close together, and both parts are relatively small. As a result the trigger can't provide as much leverage or mechanical advantage when it comes to rotating the hammer backwards as larger models can. Of course you can install lighter aftermarket springs, but then under the worst of circumstances (as opposed to the best) a cartridge may not fire.

    What they can do, without reducing reliability, is make the action smoother and in some cases eliminate unnecessary friction. This will make the trigger pull feel lighter then it really is. ;)
  12. sixgunner455

    sixgunner455 Well-Known Member

    Bianchi speed strips are still around. I usually carry my spare ammo in one -- much more convenient than a speedloader. They are all rubber now. Never saw one that was part metal.
  13. rainbowbob

    rainbowbob Well-Known Member

    I'm familiar with the various speedloader/speed stri options. That isn't the problem.

    It doesn't appear to be at all looose - it just doesn't seem to have been cut right (it sticks out a skosh to far).

    I'll ask them to do that, as well as cut back the lug ("stop").

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