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October 18, 2017
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Seems to me that the actual endplay on a Dan Wesson revolver is around .007 inch. We don't measure it that way of course, as we generally measure endplay with the cylinder at rest with the spring loaded detent ball holding the cylinder in the 'forward' position. Technically, there is more travel of the cylinder at the time of ignition. The question is then: how much does the spring tension of the detent ball affect the cylinder's 'hammering' effect during the firing sequence? A little, or a lot?
I equate this to our quickly bending our knees when we land to mitigate our 'bouncing' on a trampoline. Is this a reasonable comparison? If so; how did Dan Wesson and Karl Lewis ever calculate how much tension to place on the detent ball spring to accomplish this purpose?
Or; is the spring loaded detent ball there simply to help center the cylinder's alignment with the barrel?
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Dans Club
February 22, 2009
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Pure speculation but I imagine the detent ball is primarily there for rear cylinder lockup.
Technically, the glass is always full; half liquid, half air....
October 18, 2017
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I guess what got me thinking this way was this statement by nationally known retired gunsmith Grant Cunningham:
(Interestingly, the Dan Wesson guns are very robust in terms of their endshake handing; the spring-loading bearing detent at the rear of the frame locates the cylinder at the forward-most position every time, and also serves to absorb a bit of the recoil force of the cylinder.)
Considering how fast this all happens (one millisecond) it has always amazed me how the cylinder becomes a bouncing hammer inside the frame cutout of a revolver, and how these forces can actually stretch the frame.
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Dans Club
March 25, 2013
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Dan Wessons are so robust and the steel so strong I don't think the frame stretches the way the beautiful but weak S&W will. Manurhin also is durable. The French GIGN discovered that Smiths were worn out after 25,000 or so rounds. The MR 73 would last hundreds of thousands of rounds with no loss of accuracy. Ditto the cold hammer forged barrel. Dan Wesson took a different route. The frame and cylinder are massively strong but the barrel and lockwork can be changed out by the user easily. A Dan may be cosmetically challenged but function seemingly forever with easily replaced parts.
October 18, 2017
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The two Dan Wesson revolvers I own are both early ones, and thus have the cylinder collar hitting directly on the frame much like the Colt revolvers from the Diamondback (1966) onward. It seems to me that the end shake that develops on these guns is from the peening of the metal there rather than from the frame stretching. The Colt Trooper MK lll is an incredibly strong revolver, but they do develop some end shake over time due to this peening, as can the early Dan Wesson. When DW changed their upper crane leg to something similar to the 'old' Colt flanged crane, the peening of the cylinder collar is now a little more even over the full circumference of the collar. A much better system, and much easier to shim if need be.
But getting back to determining if the spring loaded detent ball has any advantageous affect on cylinder hammering; I'm still looking for answers. Karl Lewis could have just as easily engineered the detent ball to allow only minimal movement rather than the .007 that he ended up with, but he didn't. Since fore and aft movement of the cylinder on a revolver should always be kept to a minimum, he must have had a reason to engineer it the way he did.
Interestingly, with Colt's recent re-entry into the double action revolver market they are using a new stainless steel alloy that is the hardest and strongest material they have ever used. Peening, and, or, frame stretching will hopefully be a thing of the past for them just as it always must have been at Manurhin.
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Dans Club
March 25, 2013
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3ric, my BIL bought one of the new Colt King Cobra. I was so impressed I bought one too. 3" barrel and an incredibly smooth trigger. It was brought to my attention by my BIL that under rapid fire the trigger can fail to reset. He says Colt is working to fix that. I doubt anyone can shoot that fast with ammo as opposed to rapid dry firing. The trigger has to return enough to reset. I think it is a user problem. Glad to hear the steel is so strong. It is an incredible combat revolver and small enough to conceal carry easily. The former King Cobra was really a Trooper Mark V. Much bigger gun.
October 18, 2017
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Glad to hear you're enjoying your new King Cobra, Ole Dog. I agree that the failure to reset in rapid fire is most likely user error. I recently read an interesting review of the new Colt King Cobra written by a gunsmith who stated that he was wearing out his diamond files and stones just trying to make a minor adjustment on one of these revolvers. The steel is incredibly hard.
Still, as you stated earlier, the Dan Wesson revolvers will basically shoot forever with only occasional user friendly maintenance.
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January 24, 2009
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3ric said
Seems to me that the actual endplay on a Dan Wesson revolver is around .007 inch. We don't measure it that way of course, as we generally measure endplay with the cylinder at rest with the spring loaded detent ball holding the cylinder in the 'forward' position. Technically, there is more travel of the cylinder at the time of ignition. The question is then: how much does the spring tension of the detent ball affect the cylinder's 'hammering' effect during the firing sequence? A little, or a lot?I equate this to our quickly bending our knees when we land to mitigate our 'bouncing' on a trampoline. Is this a reasonable comparison? If so; how did Dan Wesson and Karl Lewis ever calculate how much tension to place on the detent ball spring to accomplish this purpose?
Or; is the spring loaded detent ball there simply to help center the cylinder's alignment with the barrel?
Seems to me that you would only have to merely compress the cylinder rearward until it stops, then measure the gap at the front, to acquire your answer. My guess is that it's in the neighborhood of .004~ish. And if that amount seems too large, reduce your front end gap to the .003~.004 range (the gap I set most of my DW's to), and you will be fine as long as the front of your cylinder doesn't become fouled after many rounds fired in a cession.
October 18, 2017
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I guess I'm not being clear enough in this discussion. In a Dan Wesson revolver with the cylinder at rest and the spring loaded detent ball holding it in the forward position, the distance it will move rearward until it touches the recoil shield will be approximately .007". Add to this whatever cylinder/barrel gap one chooses, and we have the total cylinder/barrel gap at the time of firing. With a gap of .006 (what is provided with the gun), plus .007 movement, that comes out to .013, which is a lot. Yet, this is the way the revolver was engineered to function.
I'm just wondering why Karl Lewis didn't reduce this endplay to a minimum instead of leaving it so large. A deeper detent in the ejector would accomplish this along with lengthening the cylinder collar. So, is there something we're not understanding as to what he was trying to achieve with the spring loaded detent ball allowing .007 travel.
October 18, 2017
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Have to admit I probably should have entitled this thread "Actual vs theoretical cylinder/barrel gap". Might have been less confusing.
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March 25, 2013
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Perhaps the cylinder gases have already entered the barrel or been dissapated by the time the cylinder fully compresses the dedent ball. Not claiming, just wondering.
October 18, 2017
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Ole Dog, I've been trying to nail down the exact sequence of events that occurs when a revolver is fired for years. Can't tell you how many articles (written by countless experts) I have read, and still there is no real consensus as to exactly what happens and when. The best part is that it all happens in one millisecond. One wonders how all of these forces, and opposing forces can act so fiercely on a gun that appears to move as one unit to the naked eye. So much talk about the adverse effects of cylinder endplay, and how it 'grows', and yet here is the Dan Wesson design that has tremendous endplay and seems to resist frame stretching as well or better than the mainstream competitors.
In this age of hyper slow motion photography it would seem possible to video a Dan Wesson revolver (for the very reason of its greater endplay) being fired and be able to actually see when the cylinder goes forward and backward, and how many times this happens before its energy has dissipated. There are of course many variables: primer, headspace, chamber wall smoothness (or coarseness), chamber throat dimension, bullet diameter, bullet material, just to name a few.
One thing is certain; the greater the operating pressure of a particular round, the more it will hammer the frame. What is interesting to me is that the hammering seems to be more on the forward part of the frame than the recoil shield. Perhaps that is due to the much smaller area on the frame compared to the larger area of the ratchet, yet this could still be a clue.
One last thought: if we hold a semi-automatic pistol very loosely when firing it there is a much greater chance of a 'stovepipe' jam since the shooters loose grip is absorbing too much of the energy that is needed to fully operate the slide. Perhaps the longer spring tensioned cylinder travel on the DW is meant to absorb some of that same energy in the millisecond it takes to complete the firing sequence. Interestingly, in 1935 Douglas Bertram Wesson recommended a gentle hold on his newly engineered .357 Magnum revolver. Felt recoil is less (although there is much more movement), and it is probably less hard on the gun as well. I think if we rigidly clamped a Magnum revolver in a vise and fired it, the frame hammering might increase exponentially. Would be an interesting experiment.
October 18, 2017
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Check this out. Very informative. Click on the settings icon, and choose .25 (the slowest playback option) to get the best effect.
No doubt here that the cylinder is fully back while the bullet is being pushed down the barrel. So, in our Dan Wesson revolvers we have to add .007 to whatever our chosen barrel/cylinder gap is to cover the detent ball spring contraction. For me that comes out to exactly .010; not that it is a bad thing, just is what it is.
August 20, 2019
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It seems because of the DW ball detent spring system traditional end shake measurements can't be done in the same way as other revolvers. Maybe end shake can't be measured on a DW? End shake tolerances of other manufacturers like S&W (which considers over .002 excessive) can't be used on DWs. The fact that DWs don't seem to suffer damage from the hammering effect of end shake makes me believe Grant Cunningham's assertion the ball detent system mitigates the hammering effect by absorbing the force. These are just deductions made from my admittedly limited knowledge. This is a very interesting topic to ponder.
October 18, 2017
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Not so sure that Dan Wesson revolvers are immune to cylinder hammering. Both of my DW's have peening both on the frame and the breech face; about the same as most other well used revolvers I've seen. Considering the forces at play we're dealing with here I really don't think that little bit of spring tension is going to have much of an effect, but I could be wrong. Nevertheless I have seen end shake mentioned many times on this forum along with helpful insights as to how to correct it. DW's are tough, but eventually the cylinder hammering will take its toll. That said; despite the peening my two .357 DW's possess little 'theoretical' end shake.
September 8, 2020
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I would think that since a Dan allows you to adjust and re-adjust the gap to compensate for wear, that the hammering is kept at a minimum, since increased gap will increase the effects of the hammering proportionately. I can see the spring numbing down reverberations, but it seems a little light to act as a shock absorber.
Mr. Chronograph always told me that keeping the clearance on the tight side kept the standard deviation down, and that also helped print better groups.
(Has nothing to do with the topic, but the wear on my 744 is minimal compared to my Smitty.)
October 18, 2017
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Adjusting the barrel/cylinder gap has no effect on cylinder hammering. The hammering is between the front of the frame and the recoil shield/breech face. I do like the "numbing down reverberations" concept though, and I agree the detent ball spring can likely do little more than that. Ultimately I think it's the hardness of the steel in the DW that takes the hammering better than a Smith, even though the S&W is forged steel and the DW is cast.
October 18, 2017
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After reading through this entire topic again, I'm realizing just how different Dan Wesson revolvers really are compared to the other brands. The ability to change barrel assemblies is just the beginning. We can customize the barrel/cylinder gap, adjust the tension of the barrel to the frame, and easily change the grip to our personal preferences. Yet the most curious invention of all is the spring loaded detent ball.
My intention in starting this topic was to gain a better understanding of just how the spring loaded detent ball system figures into the overall design. The video I included is of course not a Dan Wesson revolver being fired. I wish it was, as it could possibly have shed some light as to whether this .007 travel of the cylinder against the spring during firing actually has any effect.
Our understanding of the basic principles of physics can help us only so far, and then we have to interpret what we've seen for ourselves in our experiences with these wonderful revolvers. While I can't explain it in scientific terms I do believe the spring loaded detent ball does slightly mitigate cylinder hammering. To what extent is open to debate.
I gratefully thank all the members who have chimed in with their expertise and personal experiences with regard to this discussion!
October 26, 2008
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3Ric,
My theory, since there isn't slow motion video to prove or disprove, is that the detent acts as a bit of a shock absorber. I'd be willing to bet that it wasn't designed to do so but is a side effect of having to have some way of releasing the cylinder from the frame without the extra expense/design requirements of the latch moving something on the rear of the cylinder.
The endshake issue depends on which endshake you speak of. I've found that DW's don't suffer from cylinder endshake very often. I've had exactly 1 with more than a couple thousandths cylinder endshake most were around .001 barely detectable. That gun was a 357 supermag that had a million rounds through it or that's what it looked like anyway. Crane endshake (Yoke endshake if you're a S&W guy) is very common on Dan's. Push the crane back and then check your endshake if there's almost none then you need to replace the crane lock. I don't believe in endshake washers I believe in fixing proper crane lock normally on DW's and on the 1 Supermag I stretched the cylinder collar using the same procedure laid out for Colt's since that's what the system was closest to IMO.
October 18, 2017
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Endshake is the forward to rearward movement of the cylinder in a revolver. The fact that the cylinder on a DW is being held in the forward position by the spring loaded detent ball does not mean that there is no endshake. Once the bullet clears the cylinder/barrel gap the cylinder will immediately travel to its rearward position which is around .007 of movement.
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