Why no modern top-break revolvers?

[RugRev]

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, ??

 

[Swing]

No indication of price....

That is a kick in the knickers. If it was reasonable, I would put down a C-Note today. If it is nutso priced, no thanks.

 

[Swing]

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, ??

Interesting. Available in .357, .41, .44 Mag and .45 Colt. I reckon it never went into production.

 

[Kleanbore]

Posted by RugRev:

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, ??

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:

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.

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.

 

[Nom de Forum]

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

This is Part 2 of my reply to your post.


I can’t speak for any other Webley revolver fans but I have known about the Webley Automatic pistols and the .455Auto cartridge for decades. It is very understandable that the British War Department would issue a warning about use of .455Auto in revolvers if for no other reason than all the older black powder proofed revolvers still in use. If indeed “revolvers were regularly blowing up with the hotter .455 Auto round” and it was in nitro proofed revolvers, I have to suspect there is something very different about about the pressure curve of the .455Auto in comparison to the .45ACP/AR. Where are all the reports and warnings of Webley MkVIs “regularly blowing up” that should have been published shortly after these converted revolvers were dumped on the U.S. market decades ago? I agree with you the Webley is not “super strong”. I do think the MkVI is more than sufficiently strong for the cartridges it was intended to shoot and that is why we don’t regularly hear about the MkVI blowing-up. I don’t think people should be shooting G.I. Hardball equivalent .45ACP rounds in these revolvers. The fact that I and others have done this in the past without blowing-up our MkVIs would seem to indicate that the revolver is much stronger than the what the proof pressure rating would indicate. That does not mean I advocate using loads equivalent to .45ACP pressure levels. I would very much like to see the full text of the British War Department warn you mentioned.

 

[Nom de Forum]

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.

The problem with the Detonics top-break was more about the Detonics company than the mechanical viability of a modern top-break. No doubt about it the solid frame design is stronger and more durable. However, when I consider the thousands rounds I have put through a MkVI that are at or a little above the normal operating pressure of the .455 MkII and later cartridges loadings I have no doubt modern materials and design could make a new MkVI that would hold-up well to full power .45ACP loads. It would not be as strong or durable as a S&W N frame. It would be strong and durable enough for the lifetime round counts the vast majority of shooters would shoot through it. I really think the reason why nobody is making a modern top-break is more about expense, lack of perceived significant advantage, and customer demand than the limits of the design. Plenty of people today are shooting lower pressure cartridges like the .38Sp, .44Sp, .45Colt, and .45ACP that would not be a problem for a modern Webley. 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 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.

 

[Swing]

Back to the OP's question concerning a little top-break in a mouse cartridge. I remember NAA made a short run of stainless, top-breaks in .22 Magnum. I'd imagine a slightly larger, double-action, in .25 ACP or .32 ACP could work. If there is a large enough market is another issue.

 

[Kleanbore]

Posted by Nom de Forum:

The problem with the Detonics top-break was more about the Detonics company than the mechanical viability of a modern top-break.

That is, of course, conjecture. Capital availability, cost estimates, margin requirements, and sales projections would, of course, have entered into it.

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.

...I have no doubt modern materials and design could make a new MkVI that would hold-up well to full power .45ACP loads.

Have you calculated the stress and loads? What kind of tensile strength and shear strength would you need?

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.

Not I. The trigger pulls I have tried were awful.

I liked the idea of a Schofield, but I'm just not keen on revolvers without hammer block safeties any more.

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.

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.

 

[sawdeanz]

What about a break action but with the barrel at the 6 O'clock to lessen the force on the top strap where the lock is. Even if that helped, you would still want to come up with a better hinge system.

Another abstract design which could make reloading easier is one where the cylinder pivots from the top so that the cylinder ends up over top the frame for easier and ambi loading. I can't remember if this was an actual design or a fictional one.

 

[SFsc616171]

re: no modern top-break revolvers

Simple.

1. it doesn't come in plastic.
2. there are no means to 'tacticoll' it.
3. 'Ya's mean ah's only git six shots?'
4. The pricing would be out of reach for most normal folks, but the un-normal folks might be reaching into yo' house, tah git they own!
5. With all the current examples of folks in college today, they would be looking for the 'app' to work this thing.

 

[Nom de Forum]

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.

 

[alexander45]

I 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

 

[Nom de Forum]

Unfortunately the cylinder will blow well befor you get to test the stretchyness

That is not what I have experienced. I have seen plenty of intact cylinders of converted Webleys with play at the latch and hinge. BTW, I have been shooting various versions of Webleys since the 1970s. I have put thousands of rounds through a MkVI, a few of which were full power .45ACP. I do not recommend firing full power .45ACP because of the cylinder could fail on the very first round you fire even if it has never happened to me.

 

[jimbo555]

Why are there no modern top break revolvers? Because not enough people want one. I would like a five shot 45acp swing out cylinder snub about the size of a charter bull dog.

 

[Kleanbore]

Posted by Nom de Forum:

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.

You recall correctly, and I did not imply otherwise.

What I said was that there is every reason to believe that they built a prototype of a firearm that did not prove feasible; and (1) that they apparently had not understood the issues well enough before going into it, and (2) that in today's world, with modern design and analysis tools, any technical shortcomings might well have been detected during the design stage--and maybe even ameliorated, at least to some extent.

[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!

I respectully disagree.

It is an invalid comparison of strength to suggest a S&W top-break is as strong as the Webley.

Nor has anyone so suggested.

What I was trying to point out was that the large frame S&W hand ejector is significantly stronger than the top-break Number 3.

As a matter of fact, though I did not get into it, the hand ejector turned out to be a lot stronger than the Webley Mk. VI, too.

What is being suggested is building one that is sufficiently strong and durable enough to be economically viable not necessarily the most economically competitive.

First, it would have to work--hold up to endurance testing.

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?

"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%.

I have no idea how much improvement could be brought about via metallurgy alone. I do not know the loads or the strains at each critical point in the frame.

I do think it well within the realm of possibility that modern metallurgy would make the cylinder less apt to burst, but I haven't examined one to determine what the weak points are.

I do know that the load paths in a hinged forearm with a two piece frame create technical challenges, weaknesses, and a tendency for greater stretching in than in a solid frame revolver. That should be obvious to the causal observer without going through a loads analysis of any depth.

Perhaps you should not be so sure about what you think you know about the strength of Webleys.

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.

Jim knows far more about revolvers in general, and about Webleys (and Enfields, for that matter) in particular, than I ever will.

 

[beag_nut]

I was interested in this subject some time ago, on this or another forum. As a former design engineer I am convinced that some clever designer using ultramodern materials could come up with a durable, safe, top-break revolver design. And I would be one of the first to get one in .357 mag. We always used to (and they still do) say that "There's always a better way. Always".
Unfortunately, it takes time and money to do the job, which usually requires industry backing of some sort. So we should keep resurrecting this subject, and hope for the best. It CAN be done.

 

[Monac]

Kleanbore, this explanation of the problems involved with making high-powered top-break revolvers is why I asked if anyone had seen such stretching in a Webley 455 converted to 45 ACP. Given that such guns have been around for well over half a century, I thought some might have been shot enough to show such stretching. I have seen burst Webleys, but so far no frame-stretched Webleys. Of course, as alexander45 says, they probably burst or stretch the cylinders into uselessness before the frame stretches noticeably.

I realize that this does not affect the correctness of your point at all. This isn't just anecdotal evidence; it is the absence of anecdotal evidence. But what I would like to know is if Webley-style top-break revolvers for medium powered cartridges - say up to and including 45 ACP - are practical. 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.

(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.)

 

[JSH1]

(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.)

That makes sense to me. My understanding is that the .44 Special was designed to replicate the performance of the .44 Russian using smokeless powder instead of black powder.

 

[Kleanbore]

Posted by Monac:

I have seen burst Webleys, but so far no frame-stretched Webleys.

I have seen neither one, but over the years, I have seen photos of both frame problems and burst cylinders.

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.

The pressures of .44 Russian and .45 ACP factory loads are nowhere near comparable.

But it's more than pressure. The frame loads are determined by pressure curves and base area. Since the .44 and .45 and .455 areas are so close, the frame loads are essentially related directly to pressure.

The impracticality is not just theoretical. It is a matter of basic mechanical engineering. You have the loads on the top strap, the loads on the hinge, the loads on the latch, and the loads on the frame bottom. It stands to reason that in a top-beak revolver, the latch and the hinge are weak points. Weld everything together and you will have a stronger frame.

It somehow became lost on me also that the .44 Russian and the .44 Special were so close. The No. 3 was designed for the .44 American, but as it turned out, it could take the .44 Russian.

What I do not know is how the pressure curves of the black powder Russian and smokeless Special cartridges compare.

We know that the .44 Russian worked well enough in the No. 3. We know that S&W introduced the .44 Special in the hand ejector; that the .45 ACP was chambered in that firearm; and that handlloaders like Elmer Keith got by with putting some stout loads in the old triple lock.

We also know that the Webley Mk VI worked fine with the .455, and not so well with the .45 ACP.

What kind of changes, dimensional and metallurgical, might make the Webley design more durable with more powerful loads is a matter of conjecture.

That a solid frame would hold up better, however, is pretty well established.

 

[cluttonfred]

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?

 

[Drail]

The top break was a weak design made at a time when weak cartridges were primarily in vogue. They are not made any more simply because we have much better frame designs that will hold up over time and better cartridges.

 

[Monac]

Kleanbore, I very much appreciate your knowledgeable, patient, and well-written answers. I think I understand why what you and Jim K have been saying is true now, and I can see that, as Drail sums it up, top-breaks in anything more than low-powered cartridges would never be as good as the solid frame revolvers that supplanted them, even with medium-powered ammunition. I guess I just like mechanical novelty of a top-break - my first pistol was an H&R 999! Thanks again for the education.

 

[Billy Shears]

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?

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.

 

[Carl N. Brown]

I have a Webley Mk IV .455 "cut" for 45 ACP and have discontinued using .45 ACP in it. The cylinder has VR Victoria Regina era black powder proof marks and Victoria was queen to, what, 1902? Plus, the barrel is rifled with shallow grooves and narrow lands that will spin and stabilise a slow lead bullet, but not a fast jacketed bullet. I load .45 ACP and 45 AutoRim to BP .455 spex when I shoot mine today. But while the cylinder and barrel show typical black powder grey internally from pitting and erosion, the gun locks up tight with no play. I suspect the locking design of the Webley is sound, but hinge actions just are so yesterday, just not modern, for today's market.


(When .455 Webley went from BP to smokeless, the Mk V cylinder was made 3mm greater outside diameter to handle .455 smokeless powder loads. The Mark VI did away with the old bird's head grip and went with a modern handle. I feel Black powder era Webleys should be used only with loads that approximate the original BP loads and Mk V and Mk VI should only be used with loads that approximate the WWI era smokeless .455 Webley loads.

One thing I do notice is the Webley cylinder has a collar at front that keeps black powder residue from building up on the cylinder pin.)

 

[barnbwt]

Break actions are inherently weak; just see all those double rifles in Nitro chamberings. The break open revolver concept is not the problem, but the latch designs, which have been very cheesy up to now. Use a self-tensioning latch, and this "gap" problem goes away altogether, the shift the pivot joint closer to the barrel axis or put the barrel at 6 O clock, and stresses at the latch fall to nearly zero. In fact, if you put the joint about the bore axis, you don't even need a top strap.

TCB