Nut Boring
 

When i look up choke related threads I see lots of info from Austin Hogan about the profile of the original parker choke. There are also many threads where he seems to say that a "nut borer" was used in the barrel shop to adjust full choked barrels to customer specs. So what does a nut borer look like?
Perhaps this is discussed in the back issues section but I cant figure out how to search which issue.
Thanks

I have dozens of Austin’s original studies, charts, graphs, and writings on all things Parker. He even mentions the nut borer or the boring nut but never pictures it or even describes it fully.
If I ever find anything in his files that shed more light on this subject I’ll post it here.





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On page 100 of Peter Johnson's book ("Parker, America's Finest Shotgun"), he illustrates and describes tools and process used in the barrel and choke boring operation. I have also heard this tool referred to as a "nut borer" in this context, but can't remember when or where.

Thanks to you both. Ill look for the book.

TPS doesn't go into detail on the shape of chokes, and the tools, and I suspect Peter Johnson's references are, while historically correct, representative of early manufacturing techniques.
Charley Parker sold a lot of tooling and misc. parts to Gary Herman. Gary subsequently passed them on to me. Amongst the tooling were chamber rim cutters, and a wooden box containing more than a complete set of reamers. Many of the reamers were stamped with the full name 'Hayes' and in some cases, the initials J.H. (James Hayes)
Most of these reamers were threaded on the driving end, and one or two may have been square headed, which was the typical configuration of normal machinist's tools. "Nut Cutters" may have referred to a type of reamer (still listed as such) with a hex head, though I'm not certain of this.
The Hayes reamers with threaded ends were complete with the rods used in the boring machine. The consisted of a Morse Taper end, which was, and still is, used to couple the tool to the spindle. The rods, all about 3' long, had an adjustable stop ring. The far end was female threaded to accept the reamer itself
All of Hayes' reamers were of straight taper design, which leads me to believe, that at some point, the method, and reamer shape described in Johnson's book was no longer used. As Hayes was chief tool designer, and maker, as well as a brilliant engineer, I believe he may have played a role in Parker adopting a new choke design.
The same tool was used to bore all constrictions. This was determined by the depth, limited by the stop ring, that the barrel moved into the machine. The further it went, the larger the tool was at the point it exited the barrel. This naturally accounts for the reason that tighter chokes are longer chokes.
I have since passed all these tools onto another member/collector, who has amassed a more thorough collection of early Parker tools and history. I was especially glad they went to him because he has a family connection to James Hayes.

Edgar, maybe through your experience in the field you could explain how Parker Bros. attained the “ogee” choke profiles that Austin described and charted and plotted that I received from him. He suggests these profiles were the result of using a “boring nut”.






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Edgar could you detail the process from raw tube to finish boring? The step 1,2,3 etc. of making the tube.

I've heard the early cutters referred by different acronyms, and how that particular tool got it's name is anyone's guess, but it often came about by what it looked like. This predates a machine called a cutter grinder, and the individual flights may have been individually ground, but as I recall, their early tool was a single flight (cutting edge), which had it curved surface cut by a template, with a large relief for clearing the swarf, or chirps. The individual cutting edge had the advantage of, virtually no chatter, resulting in smooth surface. Aside from the coarse surface, chatter could make the tool go off center. Also, chatter, in a composite barrel would very likely spoil the tube entirely. As an aside, the deep hole drilling bits we made for the oil drill bit companies had an odd number of flights, and they typically were not spaced evenly. We made bits from 8" to a whopping 26" in diameter.
The early, ogee bits also predated expanding reamers. The tool was repeatedly run down the bore, and each successive pass was shimmed to increase the diameter. TPS says somewhere that the shims were pine, but I believe that didn't last long as the pine shim would become spongy with cutting oil, and impregnated swarf debris. I recall reading that the shim preferred was walnut. I believe the English used lignum vitae, which, they believed gave longer, and uniform life. The final bore may have gotten a light hone, but I wonder what the honing stone was. Carborundum, a Union Carbide invention, didn't come along for some time. In fact, the whole science of abrasives was in it's infancy.

Dan, I believe Parker bought all their barrel tubes in a "near net shape". Several companies supplied tubes and Charles Parker, in his fashion of 'Do what you do best, buy what you don't' seized the opportunity to make his own barrels by buying up the stock of decarbonized steel barrels from Tripplett & Scott, when they failed to win any significant contracts from the war dept. Those barrels were made from a semi-steel compostition, but the low carbon content yielded a very low tensile strength, making the thin walled shotgun tube only suitable for the lowest pressure ammunition.
The purchased steel barrel tubes were made by starting with a hollow billet, and repeatedly drawing it through mandrels, getting smaller, but longer with each pass. The hollow center, while rough at first, was likely bored first then, as needed, the OD turned for concentricity. This drawing process gave a very refined grain structure, and surprisingly, a very straight tube.
The making of damascus tubes is a process pretty well discussed, but involved wrapping the composite material of iron and steel around a mandrel and forge welding it into a tightly knitted, almost homogeneous material. There are several TV shows of competitive blade makers making their own blanks; some better than the dismal attempts of others. The use of flux material seems to weigh heavily in their product.
Parker and most gun makers brazed or soldered their tubes together, then constructed the lugs separately. Highest quality barrels, such as chopper lump, are tubes with the lugs an integral part of the forging, machined and them soldered together. Unlike the barrel failure of the Repro, in another thread, Chopper lump barrels can't "come apart".
The purchased tubes likely only got one, maybe two rough boring operations, before assembly. reaming and chamber cutting was almost certainly done when the two tubes were now a barrel set. Chamber reaming, and finally rim cutting, were done before fitting to the receiver. I've never run across any info describing pattern testing, or regulating, but this would have been done before the strikers, armed with scrapers and draw files, went to work.
Not quite the scale we're into, but our partner foundry, in the UK Midlands poured an HY alloy, pretty similar to HY80, and HY100, and cast the one piece turrets for the Challenger, the British Main Battle tank. Since we were already running a centrifugal pouring line for refinery cracking tubes, I proposed the idea to the MOD to let us in on the bidding for a centrifugally cast HY80 barrel blank for the 105mm NATO Howitzer. We succeeded in getting an initial contract for 40 pieces. Like all 'Gov't' work, they were still in testing when I decided I'd rather be home with my critters.

Thats very interesting, not dissimilar from what Williamsburg does to ream forged rifle barrels. A succession of reamers followed by a scraper that is shimmed with successive passes. The compression of the shims apparently cuts a slightly smaller bore at the muzzle which wouldnt be bad in a choking situation.

Aaron, I find rifle barrel making very interesting. The rifling machines are fascinating. Lancaster had a 'unique' oval boring machine, which didn't have lands and grooves, but just a slow, spiraling oval.

Interesting concept. Lancaster the town?
Barrel making is a hobby, so Im not finding any of this boring.

Thank you, i was interested to know the sequence of the different operations and you did so beautifully along with a great deal of other information.

Lancaster, the British gunmaker, not the town.

:rotf::rotf::rotf:

Parker and most gun makers brazed or soldered their tubes together, then constructed the lugs separately. Highest quality barrels, such as chopper lump, are tubes with the lugs an integral part of the forging, machined and them soldered together. Unlike the barrel failure of the Repro, in another thread, Chopper lump barrels can't "come apart".

It seems likely to me that the two tubes and lug were brazed together and then finish machined as a unit. All of mine seem to have a brass/spelter coloration indicating a much higher temp than the solder on the ribs. I assumed them to be furnace brazed in some type of fixture

"The purchased tubes likely only got one, maybe two rough boring operations, before assembly. reaming and chamber cutting was almost certainly done when the two tubes were now a barrel set. Chamber reaming, and finally rim cutting, were done before fitting to the receiver."
This choking sequence doesnt seem to allow for concentricty if the barrels were bent to regulate in the last third as is often discussed for point of impact. maybe im mixing things up on this point. Since the muzzles usually appear concentric, I assumed they were choked before assembly. Maybe the pilot can follow the curve as it is slight. Can you clarify Edgar?

There was a feature presented by Dave Suponski some 10 years ago that I published in Parker Pages, taken from a machinists handbook from the twenties or thirties that described in great detail with illustrations, the entire barrel making/boring of the Parker shotgun barrels. When I’m back home tomorrow night I’ll look it up and post the volume and issue here…. Or folks can look it up on their own copy of the Parker Pages Digital Archive.





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Ive seen that but couldnt find it again. Is there a searchable index?

I don't know if the barrel joining step was furnace done or rosebud torch, but My guess is hand torch. As Dean says, Dave Suponski wrote a good article. He had, at that time, and may still have, an unfinished barrel set completely soldered, and it was a mess of solder. The barrel makers were pretty liberal with the solder, based on what I saw in that set, and doing it in a furnace would have proved more difficult to add additional solder where it might have been needed.
I don't think the regulating process for shotgun tubes is anything like that done on double rifles, but I doubt any adjustments involved additional boring. Since there is very little documentation, I'm really only speculating.
There are a few guys still around who knew Charlie Parker, and my dad knew him because he grew up in Meriden. My dad had many Parkers, since he was a kid, and bird hunting and fondness for shotguns was synonymous with Parker. He had his uncle's Model 97, and a Model 12, but I don't ever recall him hunting with them. It would be great if Charlie had written a book and anticipated all these questions. Larry DelGrego is another who has family connections directly to the company, and I have no doubt he has more 'first hand' knowledge than any of us.

One of the most interesting things I have read in a long time.The knowledge of Mr. Spencer is amazing.

Contractors in the barrel department at Parker Bros would hold the barrels up to a light source, like a window with an opaque covering, and ‘regulate’ the tubes together this way. I believe they would simply thump them with their fist as a hammer.





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I assume you mean when they were wired, but not yet soldered.

I don’t think anybody can answer that question beyond speculation.





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Maybe not, but surely you could take an educated guess. I sure hope my soldered and finished barrels can take a fist thumpin without changes the POI.

I don’t know.. I read a story where a side-by-side shotgun had always shot way to low and the young owner complained of this to an old-time gunsmith. The old timer took the gun, sat on a stump and laid it across his spread apart knees and thumped it a couple of times then said “Try it now.” And the pattern had come up but not quite enough. A repeat performance by the old-timer brought the pattern right where it should be… Keeping in mind that this is a story from within the pages of a sporting book.

Maybe yes - Maybe no…





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Parker Brothers may have done some of what I describe here differently, but typical American maker practice was to straighten each barrel tube after it was drilled and first-pass reamed. A heavy wire or rod was placed horizontally across a frosted glass mounted in front of a window or source of light. Any crookedness in the shadow line indicated to the so-called "setter" just where to spring the tube to straighten it. Earlier on this was done judiciously with a hammer and later the practice evolved to using a mechanical press.

The next operation was to put the individual tube in a lathe and turn its exterior to approximate finished size and contour. Often it was necessary to re-straighten the bore as described because the removal of metal may have released internal stresses.

Double shotgun regulation was done after the tubes were tinned (exterior dip coating of molten solder). Both tubes were "mated" and held together by pieces of metal soldered between them and at fixed intervals to hold the tubes the correct distance apart. Great care was taken to see that the tubes were in the same plane and were properly adjusted to regulate and thus prevent cross-firing. Lastly the top rib, bottom ribs and loop lug were put in place, held together by wire wrapping and wedges. Then the assembly was heated in a furnace with powdered rosin or a soldering flux applied along with some additional solder.

Afterwards the bores and chokes were finish reamed and polished using increasingly larger diameter bore reamers, a choking (tapered) reamer and finally a pack reamer and polishing rod.

The regulation of double barreled guns has fascinated me for many years, mostly that of shotguns, as opposed to double rifles. I became aware that not all double barreled shotguns are properly regulated with just any old load early on. Some cannot be found to print the individual patterns atop each other with ANY load but often, when a side by side shotgun crossfires, all that is needed for perfect regulation of the patterns is to try different weight payloads and velocities.

This is just personal observation, but most often when one cross-fires badly it is because the payload is too light and/or the velocity too high. The last example I ran into is my dedicated quail and woodcock gun, a Philadelphia Fox 20 SWE. I wanted to use 7/8 oz. loads in it so when I first patterned it that's what I tried. They were running at about 1200 fps, as i recall. To my chagrin it cross-fired to the tune of 8" at about 20 yards, equally so with both barrels. I was sick when I saw that. Turns out that all it wanted was 1 oz. loads at about 1150 fps to put those sweet patterns right on top of each other at POA.

Thanks Frank for taking the time to go into the detail of the process that I didn’t take the time to explain, especially about the stationary wire to look through the tubes at. This is all explained in TPS as well. Again, thank you.





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Frank, What is a 'pack reamer'? Same as PAC reamer ?

Edgar, the so-called "pack" reamer was used for slow scraping or burnishing of the bores and chokes. It cut away very little metal and left them with a smooth surface and ready for the polishing rod. See attached pic which may be greatly expanded.

For info, this and my preceding reply are excerpts from my second to last DGJ article which was in the Summer 2022 issue when its plug was pulled. I requested both to be returned, and some day I may find another publisher for both.
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I sincerely hope you are able to publish it, as I find this fills in some blanks for me. I have found other references to a fine cutting/ burnishing tool, but not as it pertains to Parker Brothers.
I am especially interested in the tools which were 'expanded' by use of wedges, or shims. Peter Johnson references such tools in his book. The British also used tools, employing hardwood for increasing the cutting diameter.
Lastly, I was under the possibly false assumption the the ribs were not part of the initial soldering process, but installed in a second operation, because of the use of different, or softer solders.

This is good stuff. Intuitively i would make the leap that the pack reamer and nut borer might be the same idea, however I could be wrong,.

Link references the williamsburg barrel reaming process I mentioned. Scroll down to the "square reamer"

http://www.flintriflesmith.com/Tools...rel_making.htm

The "pack" reamer seems well suited to adjusting chokes for pattern.

These reamers, pack reamers and polishing fittings needed to have the drive rod centered within the bore - I know it was done with bushings but does anyone have an illustration of how these centering bushings were set up?





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There were no bushings on any of the rods that the reamers threaded into. It was simply a long (36"ish) hollow shaft, roughly 1/2" dia, with a morse taper on one end, a stop collar that was positioned and held in place by a grub screw, and the tool end, threaded to accept the reamer. The only one that differed was the tapered reamer for .410. That reamer was an integral part of the rod.

There is a fairly detailed explanation, including diagrams, of many of these questions in WW Greener's book "The Gun". Whether it was the improvement of barrel straightening using Parson's 1795 introduction of the wire inside the barrel method or using indirect light and tissue the descriptions are quite good. Rough and fine boring bits and the use of paper in the bit to adjust the diameter are explained with sketches. A choke boring bit is also shown and the various choke methods discussed. Even though the first version was published in 1881 he updated the next 8 editions up to 1910.

Looking for something else, I ran across these.

edit: These are pictures I had saved. I no longer have the reamers

Can you explain the one on the top?

I couldn't even come up with an intelligent guess.

Just a guess; the uppermost one might be a choke burnisher that's pulled forward from the muzzle end.

This shot isn't of much help but I think the one at the top in a previous shot may be the one in the bottom left corner of the box they came in (from Charlie Parker). It certainly appears to be reverse tapered, and was probably threaded on the shank end, but I don't see pulling it with a Morse taper fitted rod, as that would have possibly pulled from the spindle.
Perhaps the current custodian, who I won't name until he jumps in, could look them over in more detail. I just don't remember the details I failed to recognize, at the time, as important. The only thing I'm certain of is where they came from, and who made them, so have no doubt where they were employed.

And I wonder why that one is the only "cutter" with four flutes where the others all have five... is there a significance to that?




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