Roto-forged barrel
Some Ithaca shotgun barrels were roto-forged. Explain this method and the advantages.
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There is a long article describing hammer forging of gun barrels.
http://technology.calumet.purdue.edu/met/higley/Precision Shooting Magazine - November- 2005 (Vol_ 53 - No_ 7).htm
The main advantage is that once you have paid off the expensive machinery, it is fast.
The speed advantage is not how fast you can pile up barrels for inventory but how many button pullers you can shut down. And how many button puller operators you can put on other jobs... or lay off.
There was a story that Ruger bought a Krupp machine and left it idle for some time until economic conditions and orders made it profitable to start up instead of just ordering more barrels from an outside vendor; Wilson, I think.0 -
The machinery doesn't speed up just because the last payment is made.
The machinery and process are fast no matter if it's paid off or not.
Let's try this link:
http://technology.calumet.purdue.edu/met/higley/NotesOnHammerForgedBarrels.pdf
ADDED:
Guys, I was just responding to the way the sentence was written. Jeez! Write what you mean and don't leave room for misinterpretation.
Most article about firearms manufacturing are intriguing. These machines used for hammer forging are huge, expensive and NOISY. I have pictures tucked away in some file somewhere that shows them in operation. I'll look when I have a few minutes...
The product (barrels) is inexpensive but the front end cost load is huge. Not only are the machines expensive but the mandrels that they use to produce the barrels are right up there in cost as well. Some of the European makers are using mandrels with the chamber and receiver attachment points built in which require little final machining for final fit. This precludes threaded tenons of course but the Europeans are all for not letting the general public do gunsmithing anyway. The factories want to control all of the production.
Another drawback is the stresses built up in the barrel from the process. There is no chance of modifying a barrel without releasing some of the stresses, usually with bad results. Barrel blanks used to create custom rifles are out of the question because of this. Turning, threading and chambering would release the stresses resulting in aberrant shifts in straightness and concentricity. Useless for accuracy minded shooters. One of the German companies tried to bring hammer forged blanks into the U.S. and failed miserably when the blanks shifted as the machining was attempted. Brownells carried some these years ago but had to stop after we showed them the failures.
For final finished barrels, they're fine, Steyr proves that with every rifle they produce.
Best.0 -
quote:Originally posted by nononsense
The machinery doesn't speed up just because the last payment is made.
The machinery and process are fast no matter if it's paid off or not.
Let's try this link:
http://technology.calumet.purdue.edu/met/higley/NotesOnHammerForgedBarrels.pdf
I think what Hawk meant was, it's a much faster process. Therefore, the return on your money comes sooner and profits begin much sooner. The caveat to that is, produce too much supply, too fast and demand won't meet it. Price goes down. You just ended up working a lot more to get a lot less....
Anyways, that was great article on how the hammer/rotary barrel forges work.
quote:Originally posted by nononsense
ADDED:
Guys, I was just responding to the way the sentence was written. Jeez! Write what you mean and don't leave room for misinterpretation.
Sorry about that, I see what you mean. I didn't mean to get-all-up-in-yo-wheaties[:I] [;)][:D]
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"Another drawback is the stresses built up in the barrel from the process. There is no chance of modifying a barrel without releasing some of the stresses, usually with bad results. Barrel blanks used to create custom rifles are out of the question because of this. Turning, threading and chambering would release the stresses resulting in aberrant shifts in straightness and concentricity. Useless for accuracy minded shooters. One of the German companies tried to bring hammer forged blanks into the U.S. and failed miserably when the blanks shifted as the machining was attempted. Brownells carried some these years ago but had to stop after we showed them the failures."
For final finished barrels, they're fine, Steyr proves that with every rifle they produce.
Best.
That last part is another excellent piece of information. Many times have I seen 'take-off' barrels that I thought would be handy to turn into a shorter cartridge. This seems like a VERY good reason to not buy even a brand new 'take-off' unless you want that cartridge. I always knew the barrels had stresses and moved when shooting, I just never knew the result of working on them was that bad. How are they for setting back up to an inch or so?0 -
sandwarrior,
"How are they for setting back up to an inch or so?"
That's one of those questions that can only be answered with:
That all depends...
It depends on the stresses and how they relieve when the cuts are made. I've done some for demonstrations which moved very little if I was lucky and then had others that moved a lot. You can shoot a hammer forged barrel hot and see it move from center of the stock to one side or another in just a few minutes. I personally wouldn't waste my time or make the effort on a used (or new) hammer forged take off barrel. It's too easy to get a good barrel to use if the project is really worth the effort.
Best.0 -
I can say then, I'll be looking for a couple new blanks some time in the future. I had acquired a couple of used barrels to cut down and make much smaller cartridges. Thinking the stresses weren't going to be a big deal because the barrel was so much shorter.
Again, though, that is good to know.0 -
To answer the original question, Ithaca roto forged barrels will be
stronger and tougher than shotgun barrels produced by any other method.
Proper stress relieving before and after the forging process will eliminate dimensional changes from machining and barrel drift during shooting.0 -
"To answer the original question, Ithaca roto forged barrels will be stronger and tougher than shotgun barrels produced by any other method."
While this may be true in theory, it certainly didn't appear to make any difference in the survival of the company now did it. If this theory held true then all other shotgun manufacturers would have run to Ithaca, money in hand, to get them to make barrels. Besides, how strong and tough do shotgun barrels have to be to withstand the pressures exerted? Answer: Not very.
"Proper stress relieving before and after the forging process will eliminate dimensional changes from machining and barrel drift during shooting."
Again, theory is great for conversation but real world work and experience will pay the price for knowledge.
Most of the quality barrel blanks are heat treated (stress relieved) today for several reasons. This included the current variations of the hammer forging process. Unfortunately, the stress relieving doesn't always 'eliminate' the stresses accumulated through the process nor will it have the desired effect on the final barrels. This has been seen throughout the gunsmithing community. Now, there are exceptions to all things, of course, so it's not impossible to find folks to quote some source for this. But in general, hammer forged barrels are still subject to stresses contained withing the barrel due to the process.
Best.
ADDED:
For those who may be interested, here is a version of their website:
http://www.ithacagun.com/ithacabarrels.html
Here is a brief history of their iterations:
Reorganization
The company was controlled by the Smith family until 1967, when it was sold to a Colorado company which later became General Recreation, Inc. It filed for Chapter 11 reorganization in 1979. In 1987, new owners Ithaca Acquisition, Inc. moved manufacturing to King Ferry, New York. In 2005, it received a $150,000 development loan from Cayuga County, and in May of that year moved to larger facilities in Auburn, New York. After a potential buyer withdrew, however, the indebted company was closed and many of its assets sold at auction on November 29, 2005 to the Marshals of Ithaca Guns, USA LLC. Finally, David Dlubak bought the current Ithaca Gun Company and acquired the company's assets in June 2007. Since then, the factory has moved to Upper Sandusky, Ohio and undergone a total revamp, covering all areas of the manufacturing process.
Best.
ADDED yet again:
As with most of your attempt to justify your stance, you simply dance around the issue.
Real experience is what will help with the education regarding stress and metallurgy. Theory doesn't cut it and cryo treatments still leave the metal wanting.
The company failed NOT due to the introduction of M500 but from missteps and mismanagement as with most failures. The design of the M37 is still terrific and perfectly suited to general hunting but it was the company that failed not the design.
tccox,
Stress relief can be helped along with cryo and/or heat treat processes but some of the stresses still remain residual and will relieve themselves when subjected to the right set of circumstances. They are never completely and permanently eliminated. We tested dozens of barrels and tools using heat treat and cryo processes only to discover this one fact. Nothing is as foolproof as the advertising suggests. The best that can be accomplished is an average (as usual) of the failures with the cost of the treatment. Minimum failures will be tolerated if the processing is affordable given the price point and profit structure.
Best.0 -
Thanks for the information all, recently purchased an older Model 37 Ithaca featherlight and never owning an Ithaca before wanted to know the specifics about it. Has the roto-forged mark, commonplace on rifles but on shotguns, new to me.
An old rabbit hunter turned me on to them and I will have to say on the first trip out with this gun made the best shot that I have ever made with a shotgun.
Rabbit was running downhill on an open field, barren ground and was flatout blazing. After the shot, I did not see the rabbit for a bit and had to look quite a ways farther down the hill from where I shot, having rolled a good ways from the momentum. This sold me on the 37.0 -
Let me slip this in before the lock. How about cryo teatment of the barrell? Will/will not this relieve the stress?? Tom 0 -
We pretty much all know shotguns operate at lower pressure than other firearms and that all modern guns are built to withstand standard factory ammunition so strength in that context is academic.
The Ithaca 37 was a pre WW2 design. The forged barrel being stronger, allowed a thinner barrel to achieve a lightweight shotgun.
It was called Featherlite and later Featherweight at 6 1/2 pounds in 12 gauge with a steel receiver.
The superior strength of Ithaca shotgun barrels is relevant in that shotguns have thinner barrels than other firearms. As such, they are subject to denting and bulging of the tube in the field.
A forged barrel will resist deformation better and survive deep dent repair better.Ithaca's advantage was lost in the improvement over time
in the manufacture of thin wall tubes and shotgun barrels.
Depending on the stress relieving process a thin walled tube can for all practical purposes be stress free. A competitive shooter might be well advised to investigate one of the cryogenic treatments.
Ithaca went under because they couldn't compete with the much later Mossberg 500 series that came out in the early'60s and the later Remington 870 which undersold them. Both of these guns postdated the Ithaca 37 by many years and both are very good guns.Mossberg was a dead duck before the 500. It probably would have gone under in the 1960s without it.0
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