Need 11 degree forcing cone for 1858 cartridge conversion?

I have been trying to research the claimed advantages of cutting an 11-degree chamfer to the forcing cone on an 1858; when converting a percussion revolver over to cartridges. I understand in part, it's supposed to cut down on "shaving lead" when you use a cartridge as opposed to percussion ball and in theory make the gun more accurate.

I read elsewhere (I reseached here... but didn't find anything) that an 11 degree cut makes an improved difference, especially when going from .44 cap and ball to .45Colt cartridge (which is what I did).

Has anyone actually done an 11 degree cut to their forcing cone?

Secondly, what is the "standard" forcing cone cut, on black powder 1858's? In my case I have a CVA made in the 1970's... but I also wonder about Uberti, Pietta, etc. I imagine they are all close to the same, when manufactured for black powder percussion.

Knowing the difference in how a BP cone is cut, compared to how a cartridge forcing cone is cut and looks would be quite helpful to better understand this.

I found this particular video helpful to understand the process and thought I would just share it: http://www.youtube.com/watch?feature...IBv6VIQGE&NR=1

I see that Brownell's sells a 11 degree chamfer cutter tool for about $52 bucks.
They state: "No Lathe Needed, No Need To Remove Barrel From Frame. Recommended by Ron Power. The gentler entry angle causes less bullet deformation and gives better accuracy (especially important for "wadcutter" shooters). One size for all calibers from .38 to .45."

If doing such a cut is worthwhile, I'll spend the money and do it... but just don't yet understand enough about the differences between the black powder and cartridge/boolits angles to move forward.

I don't know why the forcing cone for use with cartridges would be any different from one used with balls. But what I do know is many Italian replicas don't have any forcing cone in them at all, or if they do it is small, sharp, and abrupt. I suspect this is why people find better accuracy after rethroating with the Brownells kit.

Look at your revolver and see what it has now. If it has one it should be smooth, well polished, concentric, etc.

If you do end up rethroating it, be careful. That cutter has ruined many revolver barrels when used by people who don't know what they are doing. It removes metal fast, and it takes very little to make the throat too big, which is just as bad. Then the bullet or ball expands to fill the throat and then quickly gets smashed back down into the bore. That doesn't help accuracy at all and is really hard on your gun.

If you have a lathe you can pull the barrel and throat it there also. That gives you better control of the job and it is easier to put a nice final polish on the forcing cone. Plus octagon barrels are a snap to hold in the 4 jaw chuck.

I doubt there is anything magic about 11 degrees.
If your revolver is well aligned between the cylinder and the barrel you will probably not need a huge throat.
Compare your bullet diameters, cylinder mouth diameters and barrel groove diameters.
Take a look at the alignment if you have any way to do that.
Only remove material if it makes sense. Nobade's post is good advice.
Using a lathe is much preferred. You have control of everything.

Thanks for the replies. From what I have read, it seems that the BP forcing cones are cut somewhat differently than a forcing cone designed to accept a boolit fired from a cartridge.

Maybe it has something to do with the way a ball fired from a percussion built revolver is expected to shave some lead as it enters the forcing cone, whereas a cartridge fired from a boolit is more designed to enter the bore then fill the lands and grooves in the barrel/bore? I'm probably not explaining that too well.

I looked at my CVA's 1858 and there really isn't too much there as far as any kind of throat.

As EDG mentioned "If your revolver is well aligned between the cylinder and the barrel you will probably not need a huge throat." Well, there is one problem I notice....when I look down the empty bore, with the hammer cocked back, I can see a crescent moon at 12 o'clock, a the top of all 5 cylinders starting from about the 10 o'clock position over to the 2 o'clock position. (as I cycle through them).

The cylinder to bore alignment height is basically off by about 0.70mm (measured starting from the grooves). Its would be fine from left to right but the Kirst cylinder has the bullet holes basically cut too close to center by about 0.70mm.

Bore to cylinder had aligned very well when it utilized a percussion cylinder. So, I guess I'll have to open the throat of the cone no matter what, or I'll be shaving lead at 12 o'clock.

emptythemag,
Was the Kirst konverter made for your CAV? Sounds like it's pretty close but not right. I have a CVA Walker I would like to convert but fear bigger problems than your faced with.
Ramar

Quote:

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Originally Posted by Ramar

emptythemag,
Was the Kirst konverter made for your CAV? Sounds like it's pretty close but not right. I have a CVA Walker I would like to convert but fear bigger problems than your faced with. Ramar

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Ramar, No...my Kirst kit was made for use with an Uberti 1858. They don't specifically market any of their Konversion kits for the CVA's.

I think its because the steel frame CVA's, model of 1858 are no longer produced anymore. Same with your Walker as I recall. Their 1858's are now all brass frame guns, such as those sold by Cabelas, etc.

My CVA was made back in the 1970's and from the research I did, those specs were closest to Uberti's. In fact, when I researched what Kirst had to say about using one of their cartridge Konversion kits, (with a steel frame CVA) they show under their Q&A, that you should use their Uberti Konversion kit. My guess is the Uberti parts are simply closer than the one they make to fit the Piettas.

My own personal research has lead me to believe the loading gates themselves are the same and the real difference between an Uberti and Pietta cylinder, is just a matter of the Pietta cylinder being slightly shorter in overall length.

I'm not sure about your Walker. The CVA's as we all know were sort of hit or miss as far as quality and opnions vary. I for one like CVA's and own two percussion 1860's in .44. Unfortunately both are brass frames, so I won't think about converting them over to cartridges. However, I bought them used and they both took an awful lot of work to correct barrel bore to cylinder alignment.

I'm not sure what to tell you about converting a Walker... but am concluding/thinking that Kirst will likely tell you to use their Uberti kit. But then again, I haven't researched who is/was all making Walker clones.

You could send Kirst an email or give them a call. I'm sure others have already asked them about CVA Walker conversions.

emptythemag,
Thanks for the info.
Ramar

try it and see if you have no problems and i dout you will. then the old if it iis not broke don't try to fix it kicks in. i have seen more pistols runined by people trying to improve them.

Quote:

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Originally Posted by bob208

try it and see if you have no problems and i dout you will. then the old if it ia not groke don't try to fix it kicks in. i have seen more pistols runined by people trying to improve them.

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Bob...I'm sure your trying to say something useful, to add to the discussion...but I'm not following your reply.

I'm not hung up on things like capitalization or punctuation...but your reply kinda needs a little bit of proof reading first...It sounds like something I might type after pounding down a six pack. I don't mean any offense, I just want everyone to follow your reply.

shoot the gun first see what it does. if it shoots good don't go messing with it. bullets don't know what angle the forcing cone is and don't realy care.

went back and fixed the post. some times the sugar gets higher then the shot and things go south.

Thanks for the reply bob208. Believe me...I'm not the brightest bulb, so I wasn't sure in your initial post where you were going with it... but now I follow just what you were meaning to explain.

I should just see how it shoots first, before I get too carried away and start mess with the forcing cone angle etc. Its not off so far that it will cause any sort of safety issue. I think it will just affect the bullets accuracy and put a little more stress on the gun as the boolit enters the forcing cone.

The thing that stinks is that my Kirst "cylinder to bore" alignment is not to off the left ....or to the right. If it was, I could just shim the bolt, play with the timing, etc... to create better timing. I've done this with two of my 1860's and they turned out darn near perfect.

My problem is that the conversion cylinder itself appears to sit a little too low in the frame. Its almost as if the individual 5 holes should have been drilled about 0.70mm closer to the outside of the cylinder.

Hmmmm...As I type and think about this, maybe my CVA's barrel hole wasn't drilled and tapped perfectly straight through the frame.

If the barrel is just slightly cock-eyed (pointing downward, at the business end), by that 0.70mm, this would have the same effect on the cylinder to bore not lining up. To the naked eye you wouldn't even notice it, if were only off by that much ...but the effect would be see where the bore aligns to the cylinder.

emptythemag,
Nobade and EDG have some good thoughts, but bob208 got it right(sugar helps). What's the revolver's accuracy?? Don't over think it unless perfection is achievable and you got the time.

I think you should listen here.

"I should just see how it shoots first, before I get too carried away and start mess with the forcing cone angle etc. Its not off so far that it will cause any sort of safety issue. I think it will just affect the bullets accuracy and put a little more stress on the gun as the boolit enters the forcing cone."

May I inquire of your use of "0.70mm"? Were you educated in Europe? No offense, please, just curious.......
Ramar

Ramar... I know exactly what you mean about people having low or even high blood sugar. Although not diabetic myself, I've assisted EMS on many ambulance calls and have seen first hand just how much sugar can throw you off. Often to people who don't realize it... like coworkers, ect. Too often they mistake a person with blood sugar problems for being intoxicated, etc. Most people simply don't know any better to recognize the signs; especially dangerous low blood sugar, until someone go unresponsive.

I was rambling on... so I digress....I'm not sure what the accuracy is going to be on my .45 colt conversion. I've yet to fire it since doing the swap/mods. I was just trying to do everything possible before firing it, to lessen the chances of more major issues occurring.

I feel it is alright to fire it the way it is, but just wanted to tune it up as much as possible first, since I'm just wrapping up the conversion.

I take no offense to your inquiry, as to where I was educated. I seldom take offense to anything anymore. I reserve offense only for those times when you know someones intention is to offend you. But anyway...

I wasn't educated in Europe..went to school in the USA, although I did live in Germany for 4 years, back in the late 1980's, when it was still West Germany. I remember growing up, being taught in grade school that the entire world was going to convert over to the metric system. I guess it never really caught on in the USA like they thought it would. Metric is kinda confusing to me (since I seldom use it) but quite useful no doubt.

Basically...all my scholarly metric training is based on the fact that both my digital calipers and my Auto Zone brand leaf gauge are both displayed in both inch and metric increments. I just looked at the metric reading instead of inch....no particular reason I guess.

So my 0.70mm is off by 0.0275 inches.

So do you any of guys think I'll see a problem with a 0.70mm=0.0275 inch misalignment between the barrel and cylinder?

Yes I think it is what I would consider a terrible misalignment. I think it should be about .005 or less.
.0027 would be ok but not .027.

Unfortunately I do not have access to a lathe.

I can certainly just unscrew the barrel from the frame. I had it out once before, to file the shoulder (un-threaded portion) down a little bit. I noticed the barrel's straight sides were not indexing straight with the sides of the receiver and so the front sight was just slightly off to one side. A little file work to get it a little tighter and its now pointing straight up, like its supposed to be.

But as far as cylinder to bore alignment, I'm not sure how to tackle this misalignment issue. I believe I can shoot it this way with soft lead, since the 45 colt bullet is tapered but would feel much better if I could get it closer to aligned.

There is not much of a way to do it though... since its a matter of up & down, and not side to side. Unless someone knows of something I'm missing.

just a thought from the peanut gallery...how does the center meassurement from the cylinder axle and the bore holes compare between the two cylinders... the cap-n-ball and the kirst 45 colt compare.

you said that the origanal cylinder was a good fit all around so if the new kirst is different then maybe the whole project is a bit of a bugger.

just a thought...hate to see another cva that was built when they were popular for a good utility gun go awry...had a couple myself from that era and kick myself for allowing them to go away...price of youth i think.