.45-70 Colt Walker

[Jim Watson]

Notice the part about the cylinder diameter of the Bison?
The .45-70 is not only longer than any usual revolver cartridge, it is larger in diameter.
It has a head diameter of .5039" and a rim of .608"
I doubt the Walker will accommodate a cylinder wide enough to hold it.
There are .45 Colt conversions but .45 Colt is .480" and .512", respectively.

Note that the Black Powder Magnum uses .460 S&W brass which is about the same diameter as .45 Colt.

 

[jmar]

Notice the part about the cylinder diameter of the Bison?
The .45-70 is not only longer than any usual revolver cartridge, it is larger in diameter.
It has a head diameter of .5039" and a rim of .608"
I doubt the Walker will accommodate a cylinder wide enough to hold it.
There are .45 Colt conversions but .45 Colt is .480" and .512", respectively.

Note that the Black Powder Magnum uses .460 S&W brass which is about the same diameter as .45 Colt.

Thanks for the info, some of the first that's helpful. I believe it would still work though as the walker is overbuilt from colt, and the reproductions are faithful to that. The big revolver in that picture seems overbuilt, it was built in the 60s and was probably the first of its kind, lets compare it to other big bores.

Notice how it's bigger than even the .500?

Look how slim this guns cylinder is.


Maybe now you can get a sense on just how massive the walker is.


Perhaps i should just build the thing and see if it works, if not then go from there.

 

[rcmodel]

THE POINT YOU REFUSE TO ACKNOWLEDGE IS:

The Walker doesn't have a top strap like all the other guns you show, to keep the frame from bending from the forces involved!!!!

rc

 

[jmar]

Well, it's becoming more and more apparent that you know far more about firearms design then I do.

But if you want a 45-70 single-action revolver that won't blow up?

Why not just buy one for about 10 times less then it would cost to convert a Colt Walker that will blow up the first time you shoot it??


https://www.magnumresearch.com/Firearms/Magnum-Research-4570-Revolver-75-inch-Barrel.asp

rc

Perhaps i do as you still do not understand the difference between black and smokeless powder. The gun you posted is made to fire modern 45-70s, and has 5 times the kick... You do realize a Uberti Walker is $300 and the cylinder would be about $200. hardly the 10k you said it'd cost.

THE POINT YOU REFUSE TO ACKNOWLEDGE IS:

The Walker doesn't have a top strap like all the other guns you show, to keep the frame from bending from the forces involved!!!!

rc

How many times do i need to tell you, before the walkers are shipped off they're shot with 180 grains of powder, ALMOST 3 TIMES THE 70 GRAINS I WANT maybe this thread is more suited for the blackpowder section as you do not seem to grasp that black powder has more of a pushing force than an explosive force. 70 grains of black powder has less energy and kick than a 357 magnum.

 

[rcmodel]

Not with a 405 grain 45-70 bullet in front of it it doesn't.

What part about muzzle energy & recoil is it you don't understand??

Never mind.
I'm tired of trying to reason with you on something you very obviously don't understand.

If you had ever shot a black-powder 45-70 rifle, or carbine, you would understand.
But you very obviously haven't.

before the walkers are shipped off they're shot with 180 grains of powder,

No, they are not.

The chambers won't hold half that much powder with a lead ball in front of it.

Rc

 

[jmar]

Not with a 405 grain 45-70 bullet in front of it it doesn't.

What part about muzzle energy & recoil is it you don't understand??

Never mind.
I'm tired of trying to reason with you on something you very obviously don't understand.

If you had ever shot a black-powder 45-70 rifle, or carbine, you would understand.
But you very obviously haven't.

No, they are not.

The chambers won't hold half that much powder with a lead ball in front of it.

Rc

So did you shoot a black powder 45-70? If not then what is the point in even mentioning it.

 

[jmar]

Here you go, skip to 4:40. I'm not sure how this is done with blackpowder guns but its done as it is the law and they have the proof marks to back it up.
https://youtu.be/qYOJa8ZNxmE?t=4m40s

And BTW blackpowder colts have a 3/4 inch steel rod that connects the barrel to the frame. This is called an arbor, then gun simply wont bend in half as you think.

 

[rcmodel]

Yes.
Too many times to count.

I have owned several Remington Rolling Blocks and Trap-Door Springfield's over the last 60 years or so.

Again, have you ever fired one??

And BTW blackpowder colts have a 3/4 inch steel rod that connects the barrel to the frame. This is called an arbor, then gun simply wont bend in half as you think.

Again, it's not a solid steel rod, it's not 3/4".
It is just an axial for the cylinder to rotate on.

It offers no support or strength to keep the off-center force of a cartridge firing revolver from springing the frame.

And again, you don't know what you are talking about.
And have no conception of the forces put on a handgun frame upon firing.

rc

 

[jmar]

Yes.
Too many times to count.

I have owned several Remington Rolling Blocks and Trap-Door Springfield's over the last 60 years or so.

Again, have you ever fired one??

Again, it's not a solid steel rod, it's not 3/4".
It is just an axial for the cylinder to rotate on.

It offers no support or strength to keep the off-center force of a cartridge firing revolver from springing the frame.

And again, you don't know what you are talking about.
And have no conception of the forces put on a handgun frame upon firing.

rc

No i have not, bottom line is there's is no debating that black powder is weaker and slower moving than modern powder which is why those modern ones have such fat cylinders. I've shot very hot .44 magnum loads however, which is more comparable to a walker.

Sure does look like a steel rod, no where did i say it's solid even though i believe it to be.


And this is the point i stop replying to you as nothing you've said this entire time is positive. This is what like the 3rd or 4th time you tried to insult my intelligence. Good night.

 

[rcmodel]

Great!!
But, you have not shot 'very hot' .44 Magnum loads in an open top revolver.

And good luck again!!

rc

 

[Jim NE]

I would just buy a BFR revolver in .45-70. I've held one, and although that isn't my thing, it was a rather impressive piece of metalwork. The guy who was nice enough to let me handle it had just bought it, and he was a real .45-70 fan, and knew a lot about them.

They are a lot of money, but probably less than all the hospital bills. And the ambulance...I think they charge people for that now, too...at least where I live.

 

[WestKentucky]

RC, This guy is obviously hell bent on doing this. Telling him he can't just makes it worse.

So, to do what you want to do, there is a lot of work that would have to be done. Even using black powder this is a risky undertaking because you are stepping outside of what normal use would be. The biggest issue I see would absolutely be the massive bullet used in 45-70 as opposed to a conical or round ball from the time period when the gun was designed. The bullet size and length make it hard to imagine this ever working without entirely new parts being made. Forget about modifying existing parts. You will need a new cylinder, a new frame, and hammer with firing spur. The gun would be expensive and massive. It would be very heavy.

Moving into the frame and cylinder production (hammer would be simple) the frame would take a lot of machining. Time is money, big money. It would basically be copying the back end and making the bottom portion longer. Even with a frame to use as a reference it would be slow and expensive.

Moving into the cylinder, you would absolutely have to have heat treated steel to take the pressure. Again, this sounds like a simple project. You basically stretch the length by however much you stretched the frame, and the extra bit of length will not make much difference. Now, on this part it will take a very skilled person to be able to orient and machine the various sections where the cylinder locks snd even more so the central portion when the hand comes out and rotates the cylinder. Again, a lot of time and a lot of money. Now, when you get this far you do have an arbor to worry about, again orientation, skill, time, money.

I do believe that 10k is a bit of a stretch, but I can easily see 3-4k in a merely functional gun. Nothing nice about it, but it would hold a 45-70 case, rotate the cylinder, and have the hammer necessary to make it go boom.

A much more reasonable way to get the basic gun you want would be to buy something like the BFR as has been mentioned, or start with a different platform. There were rotating rifles and shotguns coming out of Colts factories not too long after the revolver you are mentioning. If you could start with one of those platforms, you could shorten it to pistol length and the only work left to do would be to attach a grip frame and grips. You would be off to the races then.

 

[jmar]

I would just buy a BFR revolver in .45-70. I've held one, and although that isn't my thing, it was a rather impressive piece of metalwork. The guy who was nice enough to let me handle it had just bought it, and he was a real .45-70 fan, and knew a lot about them.

They are a lot of money, but probably less than all the hospital bills. And the ambulance...I think they charge people for that now, too...at least where I live.

BFR's a cool gun no doubt. But my heart lies with 19th century revolvers.
Just a funny comparison yet again on smokeless vs blackpowder.
https://www.youtube.com/watch?v=GjkOR-4zWtw
https://www.youtube.com/watch?v=SlkTCjaGmyQ

There would be more hospital bills with the BFR for broken wrists and permanent joint damage.

 

[jmar]

RC, This guy is obviously hell bent on doing this. Telling him he can't just makes it worse.

So, to do what you want to do, there is a lot of work that would have to be done. Even using black powder this is a risky undertaking because you are stepping outside of what normal use would be. The biggest issue I see would absolutely be the massive bullet used in 45-70 as opposed to a conical or round ball from the time period when the gun was designed. The bullet size and length make it hard to imagine this ever working without entirely new parts being made. Forget about modifying existing parts. You will need a new cylinder, a new frame, and hammer with firing spur. The gun would be expensive and massive. It would be very heavy.

Moving into the frame and cylinder production (hammer would be simple) the frame would take a lot of machining. Time is money, big money. It would basically be copying the back end and making the bottom portion longer. Even with a frame to use as a reference it would be slow and expensive.

Moving into the cylinder, you would absolutely have to have heat treated steel to take the pressure. Again, this sounds like a simple project. You basically stretch the length by however much you stretched the frame, and the extra bit of length will not make much difference. Now, on this part it will take a very skilled person to be able to orient and machine the various sections where the cylinder locks snd even more so the central portion when the hand comes out and rotates the cylinder. Again, a lot of time and a lot of money. Now, when you get this far you do have an arbor to worry about, again orientation, skill, time, money.

I do believe that 10k is a bit of a stretch, but I can easily see 3-4k in a merely functional gun. Nothing nice about it, but it would hold a 45-70 case, rotate the cylinder, and have the hammer necessary to make it go boom.

A much more reasonable way to get the basic gun you want would be to buy something like the BFR as has been mentioned, or start with a different platform. There were rotating rifles and shotguns coming out of Colts factories not too long after the revolver you are mentioning. If you could start with one of those platforms, you could shorten it to pistol length and the only work left to do would be to attach a grip frame and grips. You would be off to the races then.

Thank you! This is the type of reply i'm wanting, i don't need to hear all the problems i need to hear how to solve them! A cylinder and arbor don't seem like to much trouble there's plenty of skilled machinist in the world and luckily most of them have websites now. Maybe i could even send my entire walker to a skilled gunsmith.

The frame worries me though, do you mean stretch it to make it longer or cut it so a bigger cylinder can fit? Or both? I imagine the hammer can be cut and a pin inserted quite easily. I also think a better wedge could help, and i also would need an ejector. But i'm skilled enough to do those by my self. I do have ideas on how to stretch the frame but i wouldn't want to cut it myself in fear of cutting all the way to the action.

Thanks again, i'll look into those revolving rifles.

 

[WestKentucky]

By stretch, I mean stretch out the numbers when you make a new one from scratch. If it starts off at .xxx then it needs to be remade at .xxx+.yyy you don't need to take a part known to be a weak point, and intentionally add more abuse to it while either cutting and welding or simply stretching it. My wording was poor earlier. New parts, not modified parts.

And as for the frame, it needs to be both longer and have an area for a larger cylinder designed for the higher pressures. Good luck on finding anybody smart enough to run that calculation.

 

[jmar]

By stretch, I mean stretch out the numbers when you make a new one from scratch. If it starts off at .xxx then it needs to be remade at .xxx+.yyy you don't need to take a part known to be a weak point, and intentionally add more abuse to it while either cutting and welding or simply stretching it. My wording was poor earlier. New parts, not modified parts.

And as for the frame, it needs to be both longer and have an area for a larger cylinder designed for the higher pressures. Good luck on finding anybody smart enough to run that calculation.

I don't think the calculations will be that hard, first i'd bore the original cylinder to the fit the 45-70. Then simply measure the cylinder walls thickness to see if it's acceptable, if it isn't then just find the recommended thickness. Then simply take the thickness difference and that would be the number i need to cut from the frame. So bored cylinder wall = x, acceptable size = z, z-x= amount needed to be machined off frame.

Walkers seem to have lots of excess steel, is the size the only issue with the stock frame? I know how to make it longer without making a new one. Dilemma is a cylinder wouldn't be much same with an arbor, however a custom frame would be way to pricey. If strength is the issue i could send parts to be heat treated and tempered, but you cant do that with the cylinder unfortunately.

 

[rcmodel]

I keep trying to tell you that in addition to everything else, the Walker is an open top frame with no top strap to hold the pressure of that much energy and keep the frame from flexing and breaking or bending.

But you are not listening.

The open-top frame is a weak design that was outdated when black powder cartridge revolvers moved the recoil force upward from the center of the cylinder to the top of the recoil shield.

And it doesn't matter if you make it out of surplus NASA rocket steel.
It won't be strong enough to withstand 45-70 energy levels.

Rc

 

[WestKentucky]

This is where RC has been trying to make his point. The design of the gun is such that it realistically has nothing more than the wedge in the arbor holding it together. Putting the pressure of a 45-70 on that small part will likely cause catastrophic failure, and I agree. If you were simply adding force to the cylinder you would PROBABLY get by with a stronger arbor, and stronger frame since the force is concentrated on the threads of each piece. Since all of the push will be above the arbor pushing forward it causes rotational stress pushing essentially down on the front of the cylinder and the force comes in on the arbor, lower in the frame at a stronger point. That isn't what is being discussed here. Since you are moving to a cartridge type gun you are totally changing forces that act on the gun. The cylinder will no longer transfer force to the arbor and then the frame and then you...when a cartridge fires it pushes backward in the cylinder until it is stopped by a a solid piece of metal that has to be pretty stinking strong. Traditional cartridge fired guns have a top strap that in essence connects the front of the frame to the back of the frame and helps spread out the load. The walker doesn't have that, so all of the force would be on the extreme upper portion of the frame, moving directly rearward rather than kinda rotationally down and back. You would have to have a lot more metal in the frame, especially in the top end of the frame to support the force. Again, your looking at something that would require a purpose built frame from good materials with heat treat. Can it be done, absolutely. It's not too far removed from break action shotgun and rifle technology in the way that the forces would act on the frame (think NEF here), but your looking at a whole lot of labor, materials, and money. It's absolutely not worth the trouble of doing it which is why I suggested starting with the revolving rifle platform. Your talking about 6 or 8 years of firearm evolution from when the walker came about until the revolving rifles came about. Had the walker frame been sufficient for the task Colt would have used it, but it was not up to the task. Remington revolvers with the top strap were more fitting for us on cartridge guns, so Colt took their idea and used it from then on.

I know you think RC is being a party pooper, but he is giving you really good feedback. Even with modern steel, the frame is not up to the task without being improved significantly in a few ways. The most effective solution was to use a top-strap frame. If you keep pushing forward in this, to do it right you will end up with a ridiculously heavy duty custom frame, a heavy duty custom cylinder, and a lengthened heavy duty arbor. Each one will be a machine shop custom one off product with setup fees and labor out the roof.

Can it be done, yes. Should it be done, no...unless you have a dump truck full of hundred dollar bills that need to find a new home and you really want to prove it possible.

 

[Jim Watson]

One weak point of an open top Colt is the seating of the cylinder arbor in the frame. It is hard enough to get one tight, solid, and well aligned for percussion. Cartridge conversions usually come with a warning to only use light "Cowboy" loads. Enlarging everything is going to hammer on that weak point even more.

The Bison is so big because its frame is brass or bronze which is not as strong as steel.
Also, I would bet it was made as a simple scaleup without benefit of mechanical engineering analysis, so they left a lot of meat in it as a safety factor.

The cost will exceed anything you imagine. I think if you threw enough money at it, with a shop willing to tackle it in the first place, you would end up with something that looked like an enlarged Walker but with few Italian parts left in it. Back to the Bison, do you think there are many if any Colt SAA parts in it?

 

[StrawHat]

I have faith that you will get this done. Just because it hasn't been done in the past doesn't mean it can't be done. I mean, are we American'ts? Hell, no, we are Americans! We figured out how to make cigarettes that are healthy for you.We have design vehicles with computers so you can be distracted when you drive and then solved that problem by building vehicles that can drive themselves. There is no reasson to accept responsibilty for yourself, not when you have money! When you get it built make sure you video your first firing of it. I would come to watch in person but I really do not like being near explosions.

Kevin

ps, I am not sure how to post a sarcasm thingy or if there is a sarcasm font.

 

[BBBBill]

...I am not sure how to post a sarcasm thingy or if there is a sarcasm font.

Usually rendered with the roll eyes smiley face.


And I agree. This is a dangerous project that will get someone hurt. Sometime you just don't know what you don't know. This is one of them and trying to explain it is an exercise in futility.

 

[highlander 5]

What the OP is proposing is to spend a boat load of money to make a kamikaze pistol. Once completed IF he can find someone crazy enougb to do this because of the huge liability factor,I for one wouldn't want to be anywhere nearby when he fires his brain child. If he isn't killed he most certainly will be severely injured. Question to the OP,have you ever fired a handgun in 45/70? I have and can tell you right now there is no way on this planet that a black powder framed pistol is going to stay in one piece. Compare your Walker to the BFR in size and the alloy steels needed to make the 2 pistols and if you think that they are comparable and still plan to proceed with this folly I hope you have a very large life insurance policy for your family as your widow is going to need it. To repeat what others here have stated just because it can be done doesn't mean it should be done. Don't know how old you are but there those of us got to make it to a ripe old age by avoiding putting ourselves in blatantly dangerous situations I don't know you from a hole in the wall but I would like to make sure you're around to see many grand and great grandkids.







I

 

[jmar]

Do none of you realize yet that a 45-70 is only 10 more grains of BLACKPOWDER than a walker normally shoots? The extra pressure on the gun will be nothing at all especially if i have a custom thicker and heat treated cylinder. Don't even say that the projectile causes the pressures to be higher because that's false, it will have slightly more recoil as there's more friction in the barrel of the gun but nothing extra on the cylinder. And putting the bullet and powder into a cartridge actually DECREASES pressure on the cylinder walls contrary to all your beliefs.


PLEASE LOOK AT THIS CHART


Notice the differences in size and pressure of the modern powder? I don't want a BFR as the recoil is 5 times what a 45-70 blackpowder walker would be. Think of it this way, black powder is a push back while modern smokeless is a punch in the chest.


Some of you aren't even worth replying to, i didn't expect to find physicists and engineers on this forum but this is just horrible. At least read all my posts before commenting, i have already explained everything i need to. And i have come to the realization that i never needed any of your advice anyways as i pretty much have every planned out already. I just wanted to see if anyone has done something like this and get advice from gun smiths.


So to summarize the posts i've been getting.

#1 To much pressure on the cylinder.
Answer, I am resizing the cylinder if the walls are not a safe size. The sizes will be sourced from a modern 45-70. So if its thick enough to handle modern charges with 5 times the pressure than it can sure handle some old FFFG powder.


#2 Arbor
I understand the physics you are trying to explain to me, but the pressure on the arbor will be less than half a modern Colt SAA. And the thing is that the walker arbor is almost a 1/2 inch steel rod, compared to a tiny pin in other cartridge revolvers. As long as its tight the threads wont budge at all. This is why a lot of cannnons have threaded on breaches, threading is actually very strong even with a slight off center force.


#You are going to end up in the hospital.. bla bla bla.
Did you guys miss the part where i said id test the gun in a remote location behind a bullet proof object? I will test the gun with multiple powders that rate higher pressures like triple seven. I am not a redneck that will hack this thing together in my garge. All the parts will be heattreated, trued, and proofed.


SO AGAIN since some of you aren't fond of reading this is NOT meant to fire modern ammo "examine chart again", this is meant to fire the same propellant cap and ball guns usually use. The modification is for ease of reloading, not to sporterize the gun to fire arm breaking modern 45-70 rounds. OK? Seriously i don't understand why some of you are so pessimistic, sarcastic and negative. Custom guns way more ambitious than this are built every day.

I have been around the whole "newbie" forum thing many times, you all automatically assume i'm a dunce that's never shot or built anything before. But i actually have a great passion for mechanical engineering, prop and historical prop making, and even physics "mostly astrophysics". I even love working on cars and engines. I have been nothing but kind to you all, even when blatantly insulted. Sarcastic insults are not welcome, i have been nothing polite as i expect it in return. So there's my credentials boys i still have yet to know if any of you are even gunsmiths... How about before you make anymore bold claims you back up your allegations with proof okay? Links to articles, forums, and videos would suffice. Thanks



To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science.

-Albert Einstein

 

[Jim Watson]

All I can say now is let us know how it works out.

By the way, I have seen a pressure curve like that but labeled the other way 'round. A local expert found evidence that let him load smokeless for his Damascus shotgun. Must have been right, it didn't blow up.

 

[Coyote3855]

I don't have the technical knowledge to debate the OP, and he clearly is not listening to those who do. We should all just shut up, let him proceed with his project, and wish him a speedy recovery from his injuries.