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Why did we move away from Top Break Revolvers?

Discussion in 'Handguns: Revolvers' started by Aim1, May 20, 2020.

  1. Kleanbore

    Kleanbore Moderator Staff Member

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    I suppose I could make an attempt, but some of you other questions indicate that it would not be very useful to try.

    No. I would have to teach you loads analysis.

    I don't know what you think you are trying to ask.

    Simple loads analysis--geometry, mechanical advantage....

    One more time, chamber pressure is not the only determinant.

    Perhaps Driftwood, mcb, or someone else can help you.
     
  2. Old Stumpy

    Old Stumpy Member

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    Unless somebody actually builds a product-improved modern top-break revolver using the Webley stirrup latch, modern lock works, and modern steels, and then tests it with 15,000 PSI cartridges extensively, we will never know how durable it would be, or would not be.

    All predictions, pro and con are unsupported by any specific engineering data or actual test data.
    As such they are all purely speculative opinions based on personal biases.
     
  3. macadore

    macadore Member

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    I keep reading that but can't find one. Do you have a link?
     
  4. macadore

    macadore Member

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    OK, I found the 22. I was thinking about the 32 H&R Magnum. They never got around to making that, did they?
     
  5. GEM

    GEM Moderator Staff Member

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    No, it was unsuccessful and ugly according to NAA.
     
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  6. Kleanbore

    Kleanbore Moderator Staff Member

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    Not really.

    One would need test data to accept or reject a design, but not to evaluate its viability. That's done by analysis.

    It can be performed at the preliminary design stage before any really specific performance data, dimensions, or material properties have been decided upon, and refined, it it appears viable, as more is decided upon.

    We certainly do not build and test every idea that someone has in mind.
     
  7. Old Stumpy

    Old Stumpy Member

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    I find it rather tedious to be engaged in what seems yet another "You say black and I will say white" endless argument. Nothing is resolved by such spectacles, and threads have been closed for less.
    This thread should return to its original theme instead of being a two man boxing match.

    Furthermore, when the other member is also a moderator, it makes me nervous.
    Perhaps I am wrong, but it seems peculiar indeed.
     
    Last edited: May 29, 2020
  8. Kleanbore

    Kleanbore Moderator Staff Member

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    We have had more r than two members involved here. Driftwood had discussed top-break design at length. Member mcb has said that a modern top-break revolver could be designed, but that people might like the weight or the cost. I agree.

    No. I am simply pointing out a few well-known limiting design considerations.

    Speaking of of things other than engineering, mcb has opined that the issue has been primarily one of marketing. I think the fact that S&W replaced their top-breaks with hand ejectors with the same materials and for the same cartridges supports that point.

    Some years ago, we saw a prototype of a modern Webley derivative. We have seen no production models, no reviews, no sales.

    Was the demand for a new top break not there, were they undercapitalized, or did the design just fail to make the grade?

    Are you suggesting that? You have continued to talk about "modern steels" without any real specificity, and to discuss chamber pressures. None of that addresses the underlying technical issues, but we do not want to limit your discussion unduly.

    I will offer the following opinion: If there were a sufficient demand for modern top-break revolvers, and if issues of strength, durability, and producibility were readily addressable, we would see them in the stores.
     
  9. Old Stumpy

    Old Stumpy Member

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    Kleanbore, continue beating a dead horse if you wish.

    As I said, nothing will be resolved by either of us restating the same old unsubstantiated arguments over and over.

    And, it does other members a disservice to hijack a thread and to continue an endless two man boxing match.

    You win. :)
     
  10. 45 Dragoon

    45 Dragoon Member

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  11. Mauser lover

    Mauser lover Member

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    I don't think anyone has bothered to actually try explaining this yet, so I will give it a shot...

    Chamber pressure is (mostly) contained by the chamber, in this case contained in the cylinder.

    The rearward load that the frame takes is the recoil from the case head against the recoil shield (which is partly from the pressure of the combustion of the propellant, but just think of it as the recoil, because the pressure is just part of it).

    The forward load taken by the frame is from the friction (not actually just friction, but think of it that way) of the bullet traveling through the forcing cone and the bullet. The bullet "wants" to take the barrel with it. So, this is determined not by the pressure behind the bullet; but things like the frictional coefficient of the bullet material (which is why Buffalo Bore likes to use hard cast projectiles, lead is more slippery than copper), the length of the bearing surface of the bullet, the velocity of the bullet, twist rate of the rifling, and probably some other things that escape my mind at the moment.

    Recoil pushes the back half of the frame backward, while the bullet friction (again, just think of it as friction) pulls the front half of the frame forward, stressing the latch at the top/rear and the hinge at the bottom/front of the cylinder window. We need to get away from saying that a solid frame is "inherently" stronger than a top break without adding qualifications, because you can make a top break just as strong as a solid frame, it just takes more mass. If we were building solid frame revolvers out of cast aluminum and top breaks out of tool steel, that also wouldn't be a fair argument. If we keep the materials the same, the mass required to build a top break of equivalent strength to a well-designed solid frame is going to be more.

    Pressure isn't what you are fighting, which is why it has been shown to be possible to make a .357 mag top break. At least it is rumored to be extant, but I've never seen one. Look up the MP-412 Rex. Also, .22 LR as we've seen in the Iver Johnson sealed-8 and the H&R 999 is higher pressure than .45 Colt, if memory serves.

    Ultimately what you are fighting is cost of manufacture. It can be done, but it will never be done in the same way as the turn of the 20th century, because .38 S&W is no longer acceptable. Yes, .38 S&W is low pressure, but it is also low velocity and recoil. There are also issues with case length (you've gotta cam the extractor longer) adding to cost of development and manufacture. If you make a steeper cam, you'r extraction is not going to be as easy, so you need to toughen up your camming surfaces, polish the chamber(s) as much as possible, etc.

    Clear as mud?
     
    Last edited: May 29, 2020
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  12. Kleanbore

    Kleanbore Moderator Staff Member

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    There's nothing unsubstantiated about stress and loads, Young's modulus, etc..

    There's nothing unsubstantiated about the fact that there are no modern top-break revolvers in service calibers on the market.

    Hi-jack? Really?

    Technical feasibility, market demand, and cost are the substance of this thread.
     
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  13. Kleanbore

    Kleanbore Moderator Staff Member

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    Not bad at all.
     
  14. Old Stumpy

    Old Stumpy Member

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    If a top break revolver can not be made to stand up to the long-term use of 15,000 PSI handgun cartridges, then I guess that a .375 H&H double rifle is completely out of the question, or even a .416 Rigby.
    After all, that 2 piece break open action is too weak to handle a 52,000 PSI cartridge, let alone a 62,000 PSI cartridge and will loosen up rapidly. I guess that's why these rifles will never be made.

    Oh, wait.... :)
     
  15. Kleanbore

    Kleanbore Moderator Staff Member

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    Entirely different load path geometry.

    Also, they do wear, and they must be adjusted, and the adjustment provisions are built in.

    That has been discussed in this thread
     
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  16. mcb

    mcb Member

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    Man getting into the nitty gritty of pressures, load paths, geometry, joints etc is probably beyond the scope of a forum thread (unless we are going to start sharing prints and CAD models). Pressure generated by combustion is the only motive force behind basically all that stresses in the primary parts (frame, cylinder, barrel) of a revolver during the firing (excluding the internal mechanism of the fire control motivated by trigger forces). That said the actual stress are very complicated and very dependent on not only the level of pressure but also the geometry of the particular parts and they way they interact with each other. It is also not a static load condition, but is a highly dynamic event and this brings to bear inertial effects also. This is a large part of a mechanical engineering degree understanding how forces applied to parts, assemblies, and mechanisms creates motion, stress, and strain in those loaded parts. I am fairly sure a single thread here on THR cannot cover the contents of several semesters of college courses.

    As I said way up thread we could make a top break revolver is just about any cartridge you wanted but the weight and/or cost is going to get sort of silly for cartridge much over the old school 357/41/44 magnums and even those would be heavy and/or pricy.

    But there is no significant advantage to a top break 44 Mag (or similar) over more modern single action or double action revolvers. It would be market flop. It brings nothing but weight and/or cost to the game offering little or no advantages over current products.

    IMHO the only really viable market path for top break double action revolvers would be for someone to get a hold of the original prints for the S&W or Webley revolvers and make a faithful reproductions* of those revolvers using modern steels (not exotic super alloys but just good quality heat treatable alloys selected by design requirements) and modern manufacturing process. I think if marketed well and done by a competent group of engineers and machinist and marketing group this could become a money making venture but it could easily become a money pit too, real easily.

    *faith to design and cartridges would IMHO be best but I think with modern metals we might be able to substitute in more common modern cartridges of similar caliber/OAL and pressure. ie 455 Webly could probably change to 45 ACP and modern material could handle the slight increase in pressure/forces. But if I was project lead I would stay with the original cartridges. Most of the original cartridge are still available in small volumes currently. As part of your marketing plan you would be wise to make sure to bring one or more ammunition manufacture on board to supply good ammo for each of you new revolvers.

    As an engineer I must now beg the forums forgiveness for a I made the grievous sin of thinking way to hard about marketing... :rofl:

    I won't apologize for the rambling cause I want a modern reproduction of a Webley Mark VI in 455 Webley!
     
    Last edited: May 30, 2020
  17. Driftwood Johnson

    Driftwood Johnson Member

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    That is pretty much what Uberti has done. And you don't need old drawings, a good engineer can do it with good old fashioned reverse engineering. Way back around 1959, when they first introduced their replica of the 1851 Colt Navy (Which by the way is where Navy Arms got its name) Val Forgett Jr and Aldo Uberti simply reverse engineered an original. This was of course long before CAD and CNC, but reverse engineering is reverse engineering, no matter when it is done. A good engineer measures everything on an original, absolutely everything, makes up new drawings, and builds the new model from there. Which by the way is probably what the competitors were doing 140 years ago. Get hold of what you want to copy (steal), measure everything, and make your own. Of course they were running into patent laws. Forgett and Uberti did pretty much the same thing for everything that Uberti made. I think I mentioned earlier in this thread, or maybe in another similar thread that Cimarron is going to be marketing a reproduction of the American Model S&W Top Break. The owner of Cimarron sent an original American to Italy, and they used it to build a replica. It was real interesting when Uberti made their first reproduction of the Henry rifle, with its unusual barrel/magazine. Unlike later Winchesters, the barrel and magazine of the Henry rifle is formed from one solid bar of steel, and presented some manufacturing difficulties. Uberti had to figure out how to form the magazine. So like a good engineer he and Val sat down and basically came up with the same forming process that the New Haven Arms company had come up with 100 years earlier.

    That's what good engineers do. (as an engineer you probably know this) They build on what came before. It has not been mentioned here at all, but in 2000 Smith and Wesson produced the Schofield model again. They only produced this model for 2 years, and it had several design changes from the originals, but I'm sure the engineers at S&W had ample originals as well as old drawings to work from. Interestingly enough, unlike the replicas made by Uberti, the Schofield Model of 2000 was chambered for the original 45 Schofield cartridge, not 45 Colt as Uberti does.

    This thread has been going on for so long that I don't remember if I mentioned the Merwin Hulbert debacle of a few years ago here or not. Shooters have been clamoring for a modern reproduction of the Merwin Hubert for years. All the drawings and records had been lost in a fire many, many years ago. So a start up company was formed, they got a hold of an original Merwin, and measured the dickens out of it. It really is not that hard for an experienced firearms engineer. Then they created the revolver inside a computer using 3D CAD modeling. Pretty straight forward stuff. Unfortunately they ran out of money, and the gun never materialized. But all the parts had been created in 3D Cad, and any good CNC machinist can take the CAD files and create CNC programs from them. A few parts were produced, and the parts were displayed at various big gunshows around the country. And they created lots and lots of computer generated illustrations of the revolver. If they had not run out of money, I'm sure they would have produced a credible version of the old Merwin Hulbert in modern steel. Not some exotic space age steel, just good ordnance grade steel, and the revolver would have been fine for shooting cartridges such as 44-40 which many of the originals were chambered for. 45 Colt would also have been an easy cartridge to chamber it in.

    Would it have been made as a 44 Magnum or 454 Casull? Absolutely not, even with good modern steel the design was not suited for cartridges that powerful. Could it have been made in 357 Mag? A good question. On second thought, I don't think the Merwin Hulbert design would be a good candidate for 357 Mag.

    So it all gets down to how much demand is there, and how much is the customer willing to pay? Clearly Uberti has been doing this for years. If there was a market for a small S&W Top Break pocket pistol chambered for 38S&W or 32S&W, the original cartridges, I'm sure they would do it. Did I mention earlier about the cute little Colt 1862 pocket pistol that Uberti is making chambered for 380ACP?

     
    Last edited: May 29, 2020
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  18. Monac

    Monac Member

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    I think mcb's post #141 is entirely correct. I guess I want to make one point: mcb says: "But there is no significant advantage to a top break 44 Mag (or similar) over more modern single action or double action revolvers. It would be market flop. It brings nothing but weight and/or cost to the game offering little or no advantages over current products." I hate to admit it, but this is probably quite true. But couldn't exactly the same argument be made about the Colt SAA and its modern day derivatives, and maybe even to the Colt 1911? What are their advantages compared to a swing-out cylinder Ruger or a Glock or a Sig-Sauer? Sometimes things are made and are popular not because they are better technologically, but because of the fact that enough people, for whatever reason, like them.

    Of course, the questions are then A) is this true about top break revolvers, and B) what kind, or kinds, of top break revolver?.

    As to the first question, I have no idea whatsoever. I have been told that many new shooters are barely aware revolvers exist, which makes investing in any all-new revolver tooling financially dubious.

    As to the second question, the replica is one way to go. But there has also been progress since the Webley Mark VI was designed in terms of revolver trigger mechanisms and sights. I think a modernized gun in practical calibers (like 38 Special +P. 44 Special, or 45 ACP) would have potential as well. We see modernized SAA's and 1911's all over the place.

    Maybe I should buy a lottery ticket. I wonder how much I would have to win to have enough left, after taxes, to get production going from an existing manufacturer? :)
     
    Last edited: May 29, 2020
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  19. Kleanbore

    Kleanbore Moderator Staff Member

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    Different situation---mcb was talking about an all-new revolver with a hinged frame, not something historical that would appeal movie fans or people who served in the military.

    It was that appeal that brought about the resurgence of the SAA and similar firearms, and the popularity of the 1911 in the US

    A new Webley revolver might appeal to many in England, but they are not allowed to have them.
     
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  20. CraigC
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    CraigC Member

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    I can see it now. If it's a brand new design, not leaning heavily on any existing design, most revolver fans would probably say it was ugly and/or too expensive. IMHO, this is one of those situations where a few say very loudly they want one and then when it actually happens, crickets. Don't get me wrong, I'd love to see all sorts of new stuff come out all the time. Whether it was based on an existing design or totally new. However, I'm also realistic and understand that brand new revolver designs aren't really going to be marketable.
     
  21. Driftwood Johnson

    Driftwood Johnson Member

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    Well paint me green and call me a cucumber.

    I just looked up 22 Long Rifle pressures as defined by SAAMI.

    poZNOl7yj.jpg


    SAAMI Max pressure for 22 Long Rifle is 24,000 psi. Much higher pressure than 45 Colt, which is about 14,000 psi if I recall correctly.

    Who'da thunk it?

    However the much higher pressure of the 22 does not relate directly to the thrust of recoil of a 45.

    The physicists here can explain why, I am a little bit hazy on that stuff.
     
  22. CraigC
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    CraigC Member

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    Off topic but most people think the .22Mag's pressure is higher than .22LR but it ain't.
     
  23. JohnKSa

    JohnKSa Moderator Staff Member

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    Recoil is related to the momentum of what comes out of the muzzle. Momentum is the product of the mass and velocity of an object. So if we look at a 40gr bullet moving around 1100fps vs a 230gr bullet moving around 800fps, the heavier bullet would be expected to have over 4 times more recoil since it has over 4 times more momentum.

    The pressure is how you achieve momentum--that's what provides the force that pushes on the bullet to accelerate it. But there's a lot more force on a big bullet than there is on a small one at the same pressure. That's because pressure is measured in pounds per square inch. So if there are more square inches (the area of the back of the bullet is larger) then there is more force (pounds) even if the pressure is the same.

    The back of a .45ACP bullet is about 4 times larger in area than a .22LR bullet, so even at the same pressure, there will be about 4 times more total force applied to the back of a .45 bullet by the expanding gases than will be applied to smaller area that makes up the back of a .22LR bullet.
     
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  24. Kleanbore

    Kleanbore Moderator Staff Member

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    Yep.
     
  25. Driftwood Johnson

    Driftwood Johnson Member

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    Thanks for the explanation.
     
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