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So if you make the slots bigger, there would be even less material which would make the arbor weaker. The main forces are fore and aft. The wedge needs to be tight fore and aft., not necessarily "precise fit" because it's purpose is to impart tension on that union. The rest of the assembly is self aligning. A loose fit here is what causes self destruction.

So, that's why "unmentionables" and especially cap & ball revolvers of the open top design can last ones lifetime and then some if executed correctly or as designed. Believe it or not, they actually knew what they were doing in the mechanical age. Forces, vibration, harmonics . . . things that some tend to poo poo today . . .

Mike

Edited, the N,S,E,W alignment of the assembly is taken care of by the arbor/ arbor bore along with the anchoring of the barrel lug/frame joint . . . the wedge brings it all together.
But the wedge and slots still bear all of that force. You need bigger slots with more material around them to keep the wedge and slots from being deformed by repeated exposure to high pressures in that 35,000 PSI and up range.

Think about the back edge of the wedge as a blade. The narrower it is in relation to the arbor and barrel lug into which it is inserted, the more effectively it will stretch those slots. A wider wedge inserted into bigger arbors with bigger barrel lugs will provide more material to prevent that stretching.

The bottom line is that the wedge and the structures that it holds together, where it holds them together, all create a single point of concentrated stress. You need a LOT of extra material there to make such a structure hold up to the Magnum-level charges we were discussing before, and you need a wider wedge to keep it from "cutting" into the beefed up components.

Your .45 project will likely illustrate this as you continue with your experimentation. And as I said before, let me know if you need a volunteer to help do the reloading and shooting so you don't wear yourself out. 😁
 
But the wedge and slots still bear all of that force. You need bigger slots with more material around them to keep the wedge and slots from being deformed by repeated exposure to high pressures in that 35,000 PSI and up range.

Think about the back edge of the wedge as a blade. The narrower it is in relation to the arbor and barrel lug into which it is inserted, the more effectively it will stretch those slots. A wider wedge inserted into bigger arbors with bigger barrel lugs will provide more material to prevent that stretching.

The bottom line is that the wedge and the structures that it holds together, where it holds them together, all create a single point of concentrated stress. You need a LOT of extra material there to make such a structure hold up to the Magnum-level charges we were discussing before, and you need a wider wedge to keep it from "cutting" into the beefed up components.

Your .45 project will likely illustrate this as you continue with your experimentation. And as I said before, let me know if you need a volunteer to help do the reloading and shooting so you don't wear yourself out. 😁
While I appreciate your interest, the "Magnum " thing isn't gonna happen ( at least on a "belt pistol" platform). I'm only interested in the parameters that are available in the open top revolvers we have available to us. There's no reason to get to 35,000psi. 21,000 is plenty. It's Walt Kirsts project, not mine.

As far as the "stretching " you describe, I've already remedied that by taking the steps that ultimately lead to a correct build as Colt would have. So, I don't have the problems you speak of and haven't had since I've been doing what I do. I'm pretty sure that's why I was chosen to "test" one of the new cylinders.

What you describe as "how things work" is more in line with what happens with a loose wedge / short arbor setup. That's not how it works when set up correctly. The wedge install ties the barrel assy to the arbor as a solid connection ( which is why it works). When fired, the assemblage is being held in place by the arbor torqued in the frame. Any looseness or the lack of tension gives you parts that rattle against each other.

Anyway, if I WERE to build a "super open top", it would be with a "wedgeless" arbor. I drew it out several years ago as a "one of them days" thing. You'd be able to change barrel lengths from shot to shot if you wanted to and it would be on a Dragoon platform and easily run in the pressures you depict ( + some!! Lol).

Mike

Edit- I should add that the "Super Open Top" would allow for "unmentionable" ability as well as c&b.
 
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Edit- I should add that the "Super Open Top" would allow for "unmentionable" ability as well as c&b.
And capability in that unmentionable capability is where the real proof of the structure would arise.

If your one-of-these-days concept involves securing the barrel assembly from the end of the arbor where it protrudes from under the barrel, I could see it being able to hold up to a good bit more pressure.
 
If your one-of-these-days concept involves securing the barrel assembly from the end of the arbor where it protrudes from under the barrel, I could see it being able to hold up to a good bit more pressure.

Lol!!! . . . it doesn't. The arbor is completely contained in the barrel assy., it would look just like a Dragoon looks . . . minus the wedge. (Hey, but you're thinking!!!)

Mike
 
I think the stress at the wedge slot is being exaggerated. However, if Walt wants to buy 3000rds of .45ACP, I'll gladly complete the torture test before the end of the year. :D
 
Here's the thing about comparing the .357 and .45ACP. The .357 generates a lot more pressure but due to its smaller diameter, the increase in backthrust is only 8%. So you're increasing the strain on the cylinder (while greatly increasing chamber wall thickness) WAY more than that of the frame.
 
Here's the thing about comparing the .357 and .45ACP. The .357 generates a lot more pressure but due to its smaller diameter, the increase in backthrust is only 8%. So you're increasing the strain on the cylinder (while greatly increasing chamber wall thickness) WAY more than that of the frame.
So, the possibility of a "Super Open Top " 45 is a possibility! (I've already talked to folks you would know!!)

Mike
 
Super Open Top .45! Yes!

If for no other reason than the culmination of the most elegant revolver design in the history of revolver design, (and to redeem Col. Colts honor!) it must be done!
 
I don't think it's as far fetched as people seem to think. ;)
nor do I. Mikes comment about bolt guns and the surface areas in the lug/receiver interfaces is interesting particularly considering the comparative forces involved. An out of the box bolt rifle almost never has anything close to perfect engagement of those surfaces.
 
While I appreciate your interest, the "Magnum " thing isn't gonna happen ( at least on a "belt pistol" platform). I'm only interested in the parameters that are available in the open top revolvers we have available to us. There's no reason to get to 35,000psi. 21,000 is plenty. It's Walt Kirsts project, not mine.

As far as the "stretching " you describe, I've already remedied that by taking the steps that ultimately lead to a correct build as Colt would have. So, I don't have the problems you speak of and haven't had since I've been doing what I do. I'm pretty sure that's why I was chosen to "test" one of the new cylinders.

What you describe as "how things work" is more in line with what happens with a loose wedge / short arbor setup. That's not how it works when set up correctly. The wedge install ties the barrel assy to the arbor as a solid connection ( which is why it works). When fired, the assemblage is being held in place by the arbor torqued in the frame. Any looseness or the lack of tension gives you parts that rattle against each other.

Anyway, if I WERE to build a "super open top", it would be with a "wedgeless" arbor. I drew it out several years ago as a "one of them days" thing. You'd be able to change barrel lengths from shot to shot if you wanted to and it would be on a Dragoon platform and easily run in the pressures you depict ( + some!! Lol).

Mike

Edit- I should add that the "Super Open Top" would allow for "unmentionable" ability as well as c&b.
Mike, could you elaborate on this? Can't picture how a wedgeless arbor would work. Thanks, Dan
 
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