No indication of price....
I remember that one. It was listed as an upcoming product in The Gun Digest one year, and it really caught my attention. But there hasn't been anything about it since.Seem to recall years ago Detonics had a prototype .44 Mag top break displayed at a show. Wonder what ever became of it and why, lack of market, lack of durability, ??
The reason there are no modern top-breaks is simply that they are not as strong as revolvers with a solid top strap and they will eventually wear at the joint. And please no lectures about the British Webleys and how strong they are (the guns aren't strong - the ammo is weak).
In a modern revolver, the pressure pushes the case back against the breech face; that tends to try to stretch the top strap. The stronger the load, the more strain is put on the top strap. If the revolver is a top break, the joint tries to pull apart and the parts are subjected to some small amount of pounding. With each shot, the gap grows until eventually it becomes large enough that the gun won't close properly and is dangerous.
There is really no way around this. With a lot of hardened steel, wear could be delayed, but it would still occur if the ammo was hot enough. Further, the top latch itself would add complexity and cost to the product.
If anyone wants a top-break revolver, there are plenty around, including the British guns, which are very decent quality within their ammunition limitations. But if you want a top-break revolver firing .44 Magnum or even .357 Magnum, I think you will probably wait a long time.
I wonder if any Webley revolver fans ever heard of the .455 Webley Automatic pistol. If so, you might be interested in knowing that the British War Department put out explicit warnings against firing the .455 Auto cartridge in ANY .455 revolver, including the Mk VI. The semi-rimmed auto cartridge will fit and fire in revolvers chambered for the .455 revolver cartridge, but the pressure is much higher and revolvers were regularly blowing up with the hotter .455 Auto round.
So, don't tell me that Webley revolvers are super strong and can't be blown up; tell the British War Department. They thought otherwise.
Jim
Posted by RugRev: I remember that one. It was listed as an upcoming product in The Gun Digest one year, and it really caught my attention. But there hasn't been anything about it since.
I think James K answered that question pretty well on The Firing Line ten years ago next October:
Link
It's a design issue, pure and simple. I also would be concerned about the loads imposed on the hinge as a jacketed bullet is forced through the barrel.
They did show a prototype. I think one can reasonably assume that it did not fare well in testing. A solid frame revolver with similar frame component cross sections, the same materials, and a barrel screwed into the frame would be inherently much stronger.
Smith and Wesson made their last No. 3 frame before 1899, and the .44 Hand Ejector went into production shortly thereafter.
One would have thought that Detonics would have understood the issues before making a prototype, but they apparently did not.
I think they would today. There are some really neat design tools today that not only provide much higher resolution in load path calculations, but also predict stress concentration in very great detail.
I'm not sure, but I think I learned of those recently from a TV demo involving the design of bolt locking lugs for high powered rifles.
That is, of course, conjecture. Capital availability, cost estimates, margin requirements, and sales projections would, of course, have entered into it.The problem with the Detonics top-break was more about the Detonics company than the mechanical viability of a modern top-break.
Have you calculated the stress and loads? What kind of tensile strength and shear strength would you need?...I have no doubt modern materials and design could make a new MkVI that would hold-up well to full power .45ACP loads.
Not I. The trigger pulls I have tried were awful.I am on the list for the new Webley MkVI commemorative. If (big if) they do make these, and the price is not many thousands of dollars, I will buy one.
I really do not think that any company today would even consider providing a cylinder that could use factory loads with pressures half again as high as that of the proof loads for the original revolvers.I hope they have the sense to make it as strong and durable as is possible with the design. If they really want to sell more than a few of these they should have an extra cylinder in .45ACP as an option.
Posted by Nom de Forum:That is, of course, conjecture. Capital availability, cost estimates, margin requirements, and sales projections would, of course, have entered into it.
I have been around from the time before Detonics so I remember Detonics. What I recall is that Detonics disappeared for reasons due to business management problems and not a lack of engineering talent.
But for high-pressure loads with a lot of back thrust, the top-break design is not really very viable, for the reasons outlined by Jim K. S&W decided that 115 years ago, long before magnums had come into being.
Horsehockey! I am not suggesting high-pressure loads which in modern cartridges means over 30K psi. It is an invalid comparison of strength to suggest a S&W top-break is as strong as the Webley. What S&W was doing 115 years ago was attempting to build the very strongest and durable revolvers possible for economically competitive reasons. No one is suggesting this as a reason for building a modern top-break. What is being suggested is building one that is sufficiently strong and durable enough to be economically viable not necessarily the most economically competitive.
Have you calculated the stress and loads? What kind of tensile strength and shear strength would you need?
No. Nor do I think I need to. Do you really think modern steels and techniques are not sufficient to make a MkVI capable of sustained firing with loads just 30% higher in pressure when the original has routinely gotten away with occasional firing of ammunition of that pressure level? How is it that all these replica C&B revolvers using conversion cylinders for cartridges are not regularly blowing-up? Perhaps because of modern steels?
Experts advise against it and have for years, and Mark VI revolvers have known known to blow up with .45 ACCP loads. See this. One does not want to shoot 19,000 PSI loads in a revolver that was made for 13,200 PSI......
..........I really do not think that any company today would even consider providing a cylinder that could use factory loads with pressures half again as high as that of the proof loads for the original revolvers.
"The Commission Internationale Permanente pour l'Epreuve des Armes 'a Feu Portatives (CIP) rates the .455 Webley Mark II cartridge with a maximum average pressure (MAP) of 900 bar, which is 13,050 psi. At face value, this compares well to the marking stamped on the barrel of my pistol that indicates 6 tons per square inch, or (nominally) 13,440 psi. However, this 6 tons psi is actually copper units of pressure or CUP, not true psi as with the CIP value. Furthermore, it is probably base or axial copper crusher measurement per British Proof House practice, as opposed to radial or side measurement. Using the conversion of British Proof House tons per square inch in true pressure (derived from CIP data) gives 1050 bars and 15,230 psi for 6 tons psi. Since 1050 bars is squarely between the CIP rating for the .45 Colt and .45 Smith & Wesson Schofield, and consistent with SAAMI specs, I feel confident this is still a safe upper limit. I believe the 900 bar MAP imposed by the CIP was made in deference to the older blackpowder revolvers." - http://www.rathcoombe.net/sci-tech/classics/webley/webley-mk-vi.html
Perhaps you should not be so sure about what you think you know about the strength of Webleys.
Unfortunately the cylinder will blow well befor you get to test the stretchynessI don't know. Webley .455 revolvers converted to 45 ACP have been around a LONG time now, and I have never heard of one stretching into uselessness. Has anyone had direct experience of that?
Unfortunately the cylinder will blow well befor you get to test the stretchyness
You recall correctly, and I did not imply otherwise.I have been around from the time before Detonics so I remember Detonics. What I recall is that Detonics disappeared for reasons due to business management problems and not a lack of engineering talent.
I respectully disagree.[In response to "But for high-pressure loads with a lot of back thrust, the top-break design is not really very viable, for the reasons outlined by Jim K. S&W decided that 115 years ago, long before magnums had come into being"]Horsehockey!
Nor has anyone so suggested.It is an invalid comparison of strength to suggest a S&W top-break is as strong as the Webley.
First, it would have to work--hold up to endurance testing.What is being suggested is building one that is sufficiently strong and durable enough to be economically viable not necessarily the most economically competitive.
"Routinely gotten away with occasional firing" does not sound like a very prudent practice. I was referring to Jim K's comment that the .45 aCP exceeds .455 Webley Mk VI proof loads by 30%.Do you really think modern steels and techniques are not sufficient to make a MkVI capable of sustained firing with loads just 30% higher in pressure when the original has routinely gotten away with occasional firing of ammunition of that pressure level?
I am willing to accept the judgment and knowledge of Jim K on the subject, and I have simply reported what he has written on this subject--over quite a number of years.Perhaps you should not be so sure about what you think you know about the strength of Webleys.
(BTW, I was very surprised to find out that there is barely a nickel's worth of difference between 44 Russian and 44 Special, at least in their original factory loads. 44 Russian = 246 grain bullet at 750 f.p.s; 44 Special = 246 grain bullet at 755 f.p.s. That's all.)
I have seen neither one, but over the years, I have seen photos of both frame problems and burst cylinders.I have seen burst Webleys, but so far no frame-stretched Webleys.
The pressures of .44 Russian and .45 ACP factory loads are nowhere near comparable.Given that S&W was making top-break revolvers in 44 Russian, which is very comparable to 45 ACP, back in the 1870's and that they seem to have given good service, I don't understand why it would be theoretically impractical today.
Not really. There's really no advantage to the top break, even in a low powered cartridge. The speed advantage of the automatic ejection is negligible. With practice, you can open the cylinder, point the revolver muzzle upward, and push down on the ejection rod very fast -- the difference would be a matter of a fraction of a second slower than a top break. And with the swing out cylinder, with the muzzle pointed up, the empties will fall down and away, with zero chance that they can fall back down under the ejector star, which that can very easily do with a top break, which will have the muzzle pointed downward with the frame broken open, especially if the revolver isn't broken open smartly. Also, with the cylinder in line with the wrist, instead of at a 90 degree angle to it in an open top break, I expect the very slight time lost in ejection would be made up for in slightly faster reloading.It's funny how threads drift here. I started this one with photo of a .32 S&W top break, an admission that a top-break was inherently weaker than a solid frame, but wondering if there could be a market for a small top-break in a modest cartridge like .32 ACP. Perhaps it would take this thread in a more useful direction if we could talk about how to mitigate the weaknesses of a top-break to keep it safe while retaining the charm and handiness of that style of revolver?