Coning tool

[Elnathan]

Just curious, is there any period description of coning of a rifle? Did anybody ever write it down?

Spence

Spence,
I have asked this very question for each coning discussion in which I have been involved and nothing has yet been provided.

To the best of my knowledge there is no American sources for gunsmithing at all prior to around 1880. Everything we have reconstructed about how the American rifles were manufactured has been taken from European sources, and most of those deal with smoothbores.

I did take a look through Steinschloss Jagerbuschen, and while I didn't find any period source that deals with crowns or cones, I did find pictures of German rifles with the grooves filed out exactly as in the Dickert rifle illustrated earlier, plus a mention of Eric Kettenburg's July 2003 article in Muzzleblasts detailing the construction of an Austrian hunting rifle which mentions a cone about 1.5" long...So whatever we are looking at here is a German phenomenon as well.

If there is a source explaining how coning and crowning was done, it is most probably written in German.

 

[Black Hand]

The following is from 1792 (London) and deals with the forging of barrels: https://books.google.com/books?id=...KTAA#v=onepage&q=forging a gun barrel&f=false

 

[Elnathan]

The following is from 1792 (London) and deals with the forging of barrels: https://books.google.com/books?id=...nepage&q=forging a gun barrel&f=false[/quote]


Yeah, there are several European treatises, mostly, as this one does, dealing with smoothbores. Notice that he says nothing about dressing the muzzle, except to remark that Spanish barrels are "in general a little bell-mouthed?"

 

[Artificer]

To the best of my knowledge there is no American sources for gunsmithing at all prior to around 1880. Everything we have reconstructed about how the American rifles were manufactured has been taken from European sources, and most of those deal with smoothbores.

Please understand this is not criticism of you, but rather an attempt to put things into context in the period.

Technically, there was no such thing as an American source until after the Treaty of Paris was signed on September 3, 1783. Up until then, we were British Subjects/Citizens. I don't mention this to be petty or attempt to discount the information, but rather to mention if one wished to learn more of gunsmithing in the period - one would expect sources to be better from the larger gunmaking areas of England and the Continent.

Further, many of the gunsmiths here in America in the 18th century had been trained in England or Europe or had been trained by someone who had been trained there. While there are examples of 3rd or sometimes 4th generation American Gunsmiths here by the end of the 18th century, they were normally from gunmaking families whose ancestor originally trained overseas.

In many gun shops here in the American colonies, they did not have the time to entertain people "hanging around" to write about their trades and doubtless many would not have wanted "trade secrets" to get out by doing so. Even the European source documents we have only go so far into some of the details of gunsmithing and it seems obvious those gunsmiths did not describe every trade secret to Scribes who wrote about them.

We do have some period documentation on gunmaking in the National Armories at both Springfield and Harpers Ferry, from even their earliest years of production, though. However, even that documentation is rather limited to what many of us would like to know.

So we should not really be surprised there are so few early American sources on gunsmithing/gunmaking.

Finally, I wish to again state this post is not meant to be critical of any person on the forum and I do hope everyone understands that.

Gus

 

[Artificer]

I decided to once again pull out and read my copy of the Journal of Historical Armsmaking Technology, Volume III, June 1988. This Volume covers the translation of Handwerke und Künste in Tabellen [Crafts and Arts in Tables] of 1771, by P.N. Sprengel.

This work went much further into descriptions of the work and gunsmith tools than Diderot's Encyclopedie or the Portugese Espingarda Perfeyta [The Perfect Gun] of the first quarter of the 18th century. (Just want to give credit to Spence10 here, for bringing up the latter source on this forum.)

This work is important as it was "State of the Art on Rifling when it was written in 1771," and that is paraphrased from the JHAT Volume III.

I re-read this Journal and there is no mention of coning or relieving the muzzle of a rifled barrel, though there is more information on reaming and rifling than in most or all other 18th century texts.

Gus

 

[Elnathan]

There is quite a bit written about forging, boring, rifling, and even breeching barrels, but little or nothing about how they dealt with the muzzles. That includes stuff like how blunderbuss barrels were formed and filing out the rifling grooves, things we know they did. The fact that these things weren't considered worth writing down suggests to me that it was a pretty simple operation. Plus, it had to be repeatable as the barrel wore and was freshed out.

To anyone skeptical of purposeful coning, I challenge you to come up with an explanation for why barrels with at least .02 funneling at the muzzle still show rifling grooves .012-16" deep at the muzzle, 'cause I can't think of one.

 

[Black Hand]

There is quite a bit written about forging, boring, rifling, and even breeching barrels, but little or nothing about how they dealt with the muzzles. That includes stuff like how blunderbuss barrels were formed and filing out the rifling grooves, things we know they did. The fact that these things weren't considered worth writing down suggests to me that it was a pretty simple operation. Plus, it had to be repeatable as the barrel wore and was freshed out.

To anyone skeptical of purposeful coning, I challenge you to come up with an explanation for why barrels with at least .02 funneling at the muzzle still show rifling grooves .012-16" deep at the muzzle, 'cause I can't think of one.

Perhaps they didn't write much down because there wasn't anything of consequence to note (RE: Muzzle treatment). Cut, smooth and go.

As to the appearance of "purposeful" coning ("begging the question", as this statement assumes coning), wear at the muzzle could give the appearance of coning and would not obliterate the rifling. Getting a view inside the barrel to look at the height of the rifling deeper in the barrel for comparison to rifling at the muzzle would give an indication as to whether it was wear or purposeful. Even if the muzzle end was coned before rifling, one would not expect the rifling to be full-depth in the "cone" because of cutter runout - the teeth could no longer be pushed against the inside of the barrel because the barrel would flare and would not back up the cutter. The grooves wouldn't necessarily be cut full depth.

 

[Elnathan]

There is quite a bit written about forging, boring, rifling, and even breeching barrels, but little or nothing about how they dealt with the muzzles. That includes stuff like how blunderbuss barrels were formed and filing out the rifling grooves, things we know they did. The fact that these things weren't considered worth writing down suggests to me that it was a pretty simple operation. Plus, it had to be repeatable as the barrel wore and was freshed out.

To anyone skeptical of purposeful coning, I challenge you to come up with an explanation for why barrels with at least .02 funneling at the muzzle still show rifling grooves .012-16" deep at the muzzle, 'cause I can't think of one.

Perhaps they didn't write much down because there wasn't anything of consequence to note (RE: Muzzle treatment). Cut, smooth and go.

Except that they didn't always just smooth it - they filed the grooves out in many cases, both in Europe and here.

As to the appearance of "purposeful" coning ("begging the question", as this statement assumes coning), wear at the muzzle could give the appearance of coning and would not obliterate the rifling. Getting a view inside the barrel to look at the height of the rifling deeper in the barrel for comparison to rifling at the muzzle would give an indication as to whether it was wear or purposeful. Even if the muzzle end was coned before rifling, one would not expect the rifling to be full-depth in the "cone" because of cutter runout - the teeth could no longer be pushed against the inside of the barrel because the barrel would flare and would not back up the cutter. The grooves wouldn't necessarily be cut full depth.

So, you are hypothesizing that the rifling was about .025 deep originally?

The originals I've been looking at are coned, period. The question is whether it was done by the gunsmith, or by wear, or by a combination of both.

 

[Black Hand]

As to the appearance of "purposeful" coning ("begging the question", as this statement assumes coning), wear at the muzzle could give the appearance of coning and would not obliterate the rifling. Getting a view inside the barrel to look at the height of the rifling deeper in the barrel for comparison to rifling at the muzzle would give an indication as to whether it was wear or purposeful. Even if the muzzle end was coned before rifling, one would not expect the rifling to be full-depth in the "cone" because of cutter runout - the teeth could no longer be pushed against the inside of the barrel because the barrel would flare and would not back up the cutter. The grooves wouldn't necessarily be cut full depth.

So, you are hypothesizing that the rifling was about .025 deep originally?

No - I'm not hypothesizing the rifling was deeper, but it certainly could be. You said "I challenge you to come up with an explanation for why barrels with at least .02 funneling at the muzzle still show rifling grooves .012-16" deep at the muzzle, 'cause I can't think of one.", so I proposed a potential/plausible explanation. You haven't presented evidence either way...

The originals I've been looking at are coned, period. The question is whether it was done by the gunsmith, or by wear, or by a combination of both.

You are asserting they are coned, but still haven't provided much in the way of convincing evidence that this was purposefully done (otherwise the discussions would be about wear not coning) and we wouldn't be having this discussion...

 

[Elnathan]

Well, I'd disagree that .025" deep grooves fall into the "plausible" category. Quite the opposite as a matter of fact - it was intended as a reductio ad absurdum.

Also, the grooves don't go straight back, they follow the shape of the muzzle at least to some extent. I can't say if they follow a consistent depth, i.e., within a thousandth or two, but I think I would have noticed if they didn't follow the lands at all, since in order to get the measurements I usually had a caliper arm in a groove. It would be pretty obvious.

You are asserting they are coned, but still haven't provided much in the way of convincing evidence that this was purposefully done (otherwise the discussions would be about wear not coning) and we wouldn't be having this discussion...

I think a reasonably intelligent reader could figure out from context when I am talking about purposeful coning and the general shape of the bore, particularly since I have been making an effort to distinguish the two, IF they were actually reading to understand and not, hypothetically speaking, just annoyed at being told that their pet flamethrower isn't actually as PC as they thought it was.

If people want to argue that the coning (shape!) is the result of wear they need to find some explanation for why some rifles, perhaps many rifles, have the filing filed out to match the wear.

 

[Black Hand]

I think a reasonably intelligent reader...

No need to make this personal - I haven't questioned your intelligence, nor would I. However, I do question the information you have provided with respect to the measurements taken - too large a margin for error...

 

[Artificer]

I don’t believe there is any question that at the muzzle; the very ends of the lands and grooves had to be relieved, or chamfered or rounded in some manner. Had this not been done and the ends of the lands and grooves left sharp; then cloth, felt and even thin leather patches would have torn on the sharp edges left at the muzzle, most or all of the time. So it was not from a modern “accuracy reason” to relieve those edges at the muzzle like we do on unmentionable guns, but rather from a practical reason to keep from tearing patch material. Of course we know a cut or torn patch will give “flyers” in a group that will hurt accuracy and I think there is little doubt they knew that in the period as well. (BTW even on period smoothbore guns, the sharp edge left on the interior bore diameter was also relieved right after both the reaming process and the muzzle was “trued” or filed/cut as perpendicular to the bore as possible. So it was not done only on rifled barrels.)

I don’t know how far back goes the “muzzle treatment” on 7 groove rifle bores, where the lands were filed down flat at the muzzle to give the appearance of a hexagon at the muzzle and with the rifling grooves filed to what looks like full depth at the points of the hexagon?

Gus

 

[Black Hand]

I don’t believe there is any question that at the muzzle; the very ends of the lands and grooves had to be relieved, or chamfered or rounded in some manner.

Agreed - this has never been in question and would be something normally done.

 

[Billnpatti]

My opinion, for what it's worth, is to go ahead and cone your barrel if that is what you want to do. I have coned 3 or 4 of my barrels and it has had no effect on accuracy nor POI. I have a tool that is universal in that it will cone any caliber barrel. In use, you just use the correct size jag with a snug fitting patch as your guide. It works great. Unfortunately, I don't remember who I ordered it from. To use it, you just use double stick tape to adhere the various grades of emery cloth. You turn the tool with a large tap wrench. However, I will tell you that any coning tool will be a pain in the butt for the first bit of cutting because the emery cloth will catch on the lands at the muzzle and you will end up changing torn emery paper several times until you get the lands at the muzzle ground down to the point that they quit grabbing the emery paper and tearing it. :cursing: It would be so sweet if someone would come up with a similar tool only have it made of steel and have teeth like fine file teeth on it to use as a starting tool to cut down the lands to the point that you can start using emery cloth without it tearing off the tool. What the hell, I can wish can't I? :haha:

 

[Artificer]

Hi Bill,

Interesting idea on having a "universal," hand turned, rotary file to begin cutting the lands prior to using emery cloth. It is certainly possible, but as a "special made tool," the cost would most likely be prohibitive.

I am much more familiar with a universal piloted "crowning tool" that relies on a number of cutting flutes to do a bore muzzle crown. Mine is a carbide 12 cutting flute model and when I purchased it in the late 80's at the "Government Multiple Tool Rate" from Severance, it still cost $ 150.00 back then. However, I don't know what the "angle" is on most ML crowing tools, so I haven't used it yet for that job.

Gus

 

[Historian]

Necchi, thanks for bringing this back on track.

This is old but worth a try. It looks like a good tool:

Ed Hamberg
1008 Logan
Alton, Il 62002
[email protected]

Also try this, no web site:

Joe Woods, his tool highly recomended. The Firelock Shop is business in AMARILLO, 79109 United States. The Firelock Shop phone number is (806) 352-3032

Is this phone number still correct?