Muzzle coning with a file?

[Daryl]

Hmm- we're off topic.

[Mike R]

Hmm- we're off topic.

....? I was just responding to your statement. Sorry if I interjected some real history.

[Daryl]

S'OK- was good information.  I'm as guilty as any other in topic drift.

[heelerau]

I have a .50 Missouri rifle  made 35 years ago by an Adelaide Black Powder member, the barrel in and inch and 1/4 acrost the flats. He crowned the muzzel with a file, like a reverse taper, no fancy filing, and the rifle is easy to load with a .495 ball and denim patch, admittedly witha short starter, I have shot roos with it at over 130 yrds, shot 5 in a stand one afternoon.

Cheers

Gordon

[The other DWS]

When recrowning by hand with a file, how can you be sure that the reworked land ends are all even down in the bore? 

an uneven or irregular crown is considered an accuracy killer in bulleted rifles since the gasses can escape from one side before another causing the bullet to tip as it leaves the muzzle.   Or is this simply a non consideration with a tightly-patched, slightly sub-bore-diameter round ball?

[Daryl]

The eye can see quite well - especially round shapes for concentricity- it's the bottoms of the file cuts all the way around, tops of the lands (or grooves) where the filing starts.   Will they be perfect as could be cut on a lathe with a properly centered bore?  That would depend immensely on the skill of the operator of the file.

Can a good crown be cut with a file, one groove at a time - absolutely - Taylor did one on his Virginia rifle in 50 cal. Does it shoot well?  I invite you to compete against him and try to best his shooting abilities with that rifle or any other he's 'crowned'.

Filing is not my favourite method- one I tried once, but can see it's attraction and use - however I prefer to use emery and the barrel chucked in a lathe - a perfect crown is only about 20 seconds away once set up for.

As far as coning, much depends on what your definition of coning is. I call my crowns, radiused or smooth crowns, not cones.  Others might call them cones, however, when I think of rifle muzzle prepared cones, I think of icecream cone shaped crowns with long, sloping angles with the cone being about 1/2" to 1 1/2" from top of the lands to the bottom of the grooves at the muzzle's surface.

[The other DWS]

daryl,  when you do a "smooth" or "radiused" crown.  How much of the land height at the lip of the muzzle do you leave standing?  How far down do you take it,  say half the diameter of the ball IE .25 in for a 50 cal? 

Since, (assuming I'm understanding this all correctly )  with a well patched round ball the rifling only grips the compressed patch and does not impinge on the surface of the lead ball itself; it seems to me a 1/3 or even a 1/2 of the original land height would be adequate to maintain even rotation and a clean clearing of the muzzle while still allowing moderate thumb pressure to start the well-lubed patched ball.

[Daryl]

When loaded, the ball is heavily marked by the cloth covering the lands and lightly marked by the cloth compressed in the bottom of the  grooves.

To answer your question directly, the very surface at the muzzle is below groove depth, with the smoothed angle out to the tops of the lands perhaps using 1/8" to 3/16" maximum of the barrel's length.  A patch and ball will sit on top of the crown, but leaning the rifle barrel over will cause it to roll off. It cannot be soved into the muzzle with your thumb.

The top barrel is a short section of barrel I purposely made a deeper crown on for load testing ITX hard-swaged balls. That is why it has a slightly different crown.  It really loads lead balls and 10ounce denim easily. It has shallow rifling- no more than .005"- maybe .006" deep at the most and therefore is not suitable for heavy patches and bore sized balls. It's crown is a good 3/16" deep/long.

The largest muzzle is my 14 bore rifle's muzzle, which shows a crown of only about 1/8" deep with it's .012" rifling depth. At about the 11:00 o'clock position, you can see some rod wear in the corner of a groove next to the land. This was done with a tool-steel rod that I used to use for cleaning and loading ar the range.  In thinking this over, it took maybe 5 years to do that and perhaps close to 3,000 shots and cleaning every 50 or so with that rod. It does not effect the accuracy that I can tell.  I'm still able to put the first 5 into a 3" group at 200 yards off the bench.  None of these barrels has rifling over .012" deep. Deeper rifling might extend the 'length' of the taper to 3/16", I'd guess, certainly not more.

As you can see, I do not use a file for crowning. I did read an article on Muzzle Blasts about a fellow who does, and the looked just great.

[Don Getz]

I first got into "coning" the muzzles of some of our barrels at the request of John Bivins. He would the do those "cute"
muzzles by some fancy filing.    I have done many barrels that way, especially at the Conner Prairie workshops.  When
you cone a barrel you are merely putting a taper on the lands to the point of where the grooves will taper out to the
very muzzle end of the barrel.   To do that fancy filing I would first use a round file, a chain saw file works great, to
deepen the groove at the muzzle.  I would then file a small "V" groove right in the middle of the land, about 1/8" long
with a three cornered file.    After that, I would carefully round off the area between the v groove and the round groove
of the barrel, leaving these two nice little humps, slightly resembling a "baby's hiny", therefore I would refer to it as my
"Hiny" muzzle............Don








v"

[Dphariss]

I'm sure this is going to start another war, but here goes.
Yeah,  I've read the article.  Don't agree with most of the conclusions.  I won't get into the details, but just to say.... I've coned at least 10 barrels with absolutely no ill effects ( unless you call easier to load an ill effect.
Below, is the first 5 shots out of that brand new, freshly coned  barrel.  Before working up a patch/ball combo, powder charge, or regulating sights.

A smoothbore or a pistol will shoot small groups at 25 yards.
Do 5 groups at 50 or 100.

Dan

[Dphariss]

Someone, in a similar discussion, mentioned that the term back in the day was "freed". The current practice of coning is an extreme form of this practice.
The only known, by me, example of an accurate description of a  choked and freed bore on a rifle is in John Baird's  "Hawken Rifles" where Tom Dawson had detailed the dimensions. They also shot the rifle with various loads.
Its FAR different than what is done today.
The current practice of coning is a fad IMO. There is no way it cannot be a detriment to accuracy when carried to the extremes I see in posted here..

Dan

[The other DWS]

I wonder if there is not a fair amount of confusion when it comes to the term "coning" .  It seems like it is being used to cover everthing from simply breaking the sharp edge of the rifling at the muzzle to keep patches form snagging to funneling out the bore and rifling as well for an inch or more from the muzzle. 

As a relative new person to the site,  it seems to me that we have a tendency to mis-apply 18th century requirements and practices in our modern environment.  The need to reload as rapidly as possible in a dangerous game/combat situation back then might well have outweighed gilt-edged target-quality accuracy, so a funneled out muzzle that let you spit a ball well down might have had real virtue.  (or we may simply be looking at badly rod-worn muzzles)  If you are making an exact duplicate of course you would make it the way it looks now, or the way you think it looked when it left the maker's hands.    I believe too that in the course of a season we may shoot our rifles more that a lifetime of use back then.  This more intense usage may also alter the way we build and care for our arms.

I can see breaking the sharp edge on a modern-built LR a bit, perhaps even "recrowning" the muzzle to groove diameter to facilitate loading.  But funneling the rifling out for an inch or more seems counter productive; UNLESS, because of our long barrels, slow rate of twist, and tightly patched round balls a very symmetrical reduction in the rifling has little effect.   (Has anyone seen any high speed film of how a PB exits the muzzle and how the patch and ball separate?)

[Daryl]

to funneling out the bore and rifling as well for an inch or more from the muzzle.  

This is what Dan is talking about - the result you get from the various coning tools being sold today. Some of us see it as counter productive.  

This result is similar to the machining that is given to a false muzzle on a bench rest gun.   If indeed, there was no loss of accuracy due to such coning, I hold that a removeable false muzzle would never have been invented and would be used today for match rifles.

There was an article some time ago in Musket Blasts about a gun maker who filed his muzzle crowns.  He turned the lands into grooves using a file, which allowed his fairly easy loading.  Thus, the actual rifling groove was then the smallest part of the bore, at the very muzzle.  that resulting corner would have to be just barely 'broken' to allow a heavily compressed load to enter as we use some compression in the bottom of the grooves.  Practise and a good eye would make for an even crown, doing it this way.  I recall him writing that it only took 15 minutes to file a crown on his muzzles.

[Dphariss]

I wonder if there is not a fair amount of confusion when it comes to the term "coning" .  It seems like it is being used to cover everthing from simply breaking the sharp edge of the rifling at the muzzle to keep patches form snagging to funneling out the bore and rifling as well for an inch or more from the muzzle. 

As a relative new person to the site,  it seems to me that we have a tendency to mis-apply 18th century requirements and practices in our modern environment.  The need to reload as rapidly as possible in a dangerous game/combat situation back then might well have outweighed gilt-edged target-quality accuracy, so a funneled out muzzle that let you spit a ball well down might have had real virtue.  (or we may simply be looking at badly rod-worn muzzles)  If you are making an exact duplicate of course you would make it the way it looks now, or the way you think it looked when it left the maker's hands.    I believe too that in the course of a season we may shoot our rifles more that a lifetime of use back then.  This more intense usage may also alter the way we build and care for our arms.

I can see breaking the sharp edge on a modern-built LR a bit, perhaps even "recrowning" the muzzle to groove diameter to facilitate loading.  But funneling the rifling out for an inch or more seems counter productive; UNLESS, because of our long barrels, slow rate of twist, and tightly patched round balls a very symmetrical reduction in the rifling has little effect.   (Has anyone seen any high speed film of how a PB exits the muzzle and how the patch and ball separate?)

I don't have a problem telling a crown from a cone.
Of course I don't know what some people would call this on a 58 GM barrel.


I cut the crown on a lathe and since its primarily a hunting rifle I did a second cut as seen here. It is so close the the muzzle  that I cannot see a problem with accuacy, no complaints to date from the owner but it will probably load a little easier.
This is a piece of the same barrel reduced to 1" across the flats I made into a pistol. It has a single angle crown and loads fine, I use the captured rod as a starter and shoots well enough the owner says he would not hesitate to shoot at elk at 50 yards with it.



The Hoffman and Campbell built Hawken that Baird and Dawson tested had a maximum freed area right at the muzzle and it was about 10% that often done today with a coning tool. Many people appear to be removing .015-.020 and its simply not needed.
This thread will give measurements of an original barrel.
Note that the "cone" (if we choose to call it such) is not a straight taper another fact that seems to be lost on most "moderns".
Dan

[Bob Roller]

That is a cross betwixt a crown and a cone so I would call it "Croneing".

Bob Roller

[Larry Pletcher]

snipped. . . . . . .  (Has anyone seen any high speed film of how a PB exits the muzzle and how the patch and ball separate?)

DWS,
I've done high speed of the ball exiting the muzzle and also high speed stills of the patch and ball separating. In both instances, I doubt if what I got will help with answers about the coning discussion.  Below are a couple of the ball shedding the patches:


In the first photo we were using Goex ffg.  Sparks were a huge problem. The ball is 6-8 feet from the muzzle with the patch already shedd.




In these last two we used Swiss ffg.  The ball is 24" from the muzzle.  Bill Knight told me that Swiss grinds their charcoal much finer than Goex does, and this is the cause of the sparks.

As for the high speed video of the ball exiting the muzzle, you can find that at www.blackpowdermag.com .  Look down the page for the earliest high speed video - 2007 -if memory serves.

Regards,
Pletch

[The other DWS]

Thanks Pletch, those are fascinating pictures.  I was curious about the way the patch unwrapped from the ball.  It appears that the spin opens it up rather than "air-drag" peeling it off the ball--or at least it initiates the process.

 I know I tend to "over-think" things--too much time to think while driving I guess---but in the context of funnel-ized barrels I was wondering about patches prematurely releasing in the enlarged part of the bore and its potential for disturbing accuracy.  But I guess that whatever the process is, if it is consistent shot-to-shot the impact on accuracy would be less than a lot of other factors.

[Daryl]

Thanks Pletch, those are fascinating pictures.  I was curious about the way the patch unwrapped from the ball.  It appears that the spin opens it up rather than "air-drag" peeling it off the ball--or at least it initiates the process.

 I know I tend to "over-think" things--too much time to think while driving I guess---but in the context of funnel-ized barrels I was wondering about patches prematurely releasing in the enlarged part of the bore and its potential for disturbing accuracy.  But I guess that whatever the process is, if it is consistent shot-to-shot the impact on accuracy would be less than a lot of other factors.

With a relieved muzzle like a long cone, the patch will indeed be trying to spin off the ball, as well as the powder gases charging past it on all sides. If indeed, everythign is perfectly balanced, nothing is injured - again, if coning improved accuracy, don't you think the bench rest shooters would use it instead of a false muzzle?-- It would not make sense not to use a cone- even in a modern rifle- if coning improved accuracy- to do otherwise would gaurantee defeat. No cones so they must not be good for accuracy - quite simple, actually.