Tuners Spinning Out Of Control

My 2 cents from a materials standpoint is that the residual compressive stresses from button rifling will cause a barrel to behave differently than a barrel with cut rifling. I suspect that the button rifled barrel will want to stay "straighter" in general than a cut rifled barrel (like a pre-stressed beam). I also suspect that a cut rifled barrel will want to behave in a more natural, relaxed manner than a button rifled barrel. This is just postulation, but we can definitely expect differences in material behavior depending on residual stresses.

SteveM.

Jetmugg & Gordon
From a mechanics of materials standpoint that theory doesn't hold true. I'll admit that it would seem logical, but the proof and the math say otherwise - stiffness is not that closely tied to presence or absence of internal stresses - or heat treat properties either. Dead soft or hard or any combination in between the stiffness works out the same.

This property is very closely tied to the Youngs Modulus of the material which does not change so long as the material is not stressed beyond it's elastic limits. And past that limit the steel will not return to it's original shape. This would not be a good thing in a rifle barrel as it is what has happened when you form a ring in a barrel.
 
Last edited:
Steve
With no disrespect to any af the barrel makers. I find (and it is just my oppinion) that the cut barrels are much straighter. Can the stress relief not be what one think it is. When those buttons go through a barrel and the metal flows behind it the pressure must be enormous.
 
Vibe - I'm right there with you on the Young's Modulus issue (it varies only the smallest, almost immeasurable amount with respect to heat treatment, hardness etc). And of course, the barrel has to respond in an elastic manner. I was thinking in terms of having to overcome any compressive or tensile stresses before the material could respond in a "natural" relaxed manner. (Amplitude of the wave form). I'm prepared to be wrong on that item, but was envisioning the entire barrel as being in tension or compression, and how that might affect the state of tune.

Gordon - I think you are right on. It takes a helluva lot of force to push barrel steel around like it's silly putty.
 
When those buttons go through a barrel and the metal flows behind it the pressure must be enormous.
A little off topic, but you should watch the process of making copper tubing some time....they start with a solid 12" dia round bar about 24"-30" long and start shoving and pulling it thru dies - inside and out - until it's the final diameter they want. The inside dies reminded me a lot of the rifling buttons, just without the lands/grooves.
 
now vibe is talking about something i know about now. i used to work for a company called atr. we made the wire that goes in car tires. when we started the process of making it we had to run it through dies starting with a large diameter wire and ending the process with a wire onlt .030 mm's. when you run the wire through the die it does two things. it stretches the wire and it draws it down to a smaller diameter. we would stop the machine before we ran out of wire on a spool of 1.68 mm wire. we always had a new spool sitting there ready to weld together and run it through the machine. a welded spot would be maybe 3 inches long before running it through the machine. we would have to jog the machine till the 3 inch weld spot started onto the spool. then we would mark the distance down that it started onto the spool and then we would mark down the distance when it stopped. it was easy to tell. the gold colored wire would be gray where the weld was. well that 3 inch weld was often 25-40 feet long depending on just how much you ground down the weld.

vibe, how does this process remind you of a rifle buttons? finally you have said something i can understand man. if you don't care dumb your answer down so others can under stand as well.
 
Mr. Nobody - I once worked for Armco steel, who made the wire rod that was used to draw tire bead wire. We supplied places like Union Wire Rope, Leggett & Platt, and Bekeart (sp?) who made tire bead wire. That's a very similar process to tube drawing.
 
Well, since I've also got some history in wire drawing (I spent 7 or 8 years with 2 copper wire and cable companies, and toured Tokusens plant in Conway a few times). I watched the tube drawing process during a job interview - it was a great interview, I just wasn't as great as one of the other applicants. C'est la vie.
The difference in wire drawing and tube drawing is that tubing has a hole in the middle so it required a die "button" to be placed almost at the same place as the outer die - as you can imagine, it will not just "float" there by itself, so it was mounted on a very long mandrel and the tubing was drawn from billets that were just shorter than this mandrel length, using a pulltrusion method. Once started the tubing was both pushed AND pulled thru and over the dies. The billets were induction heated before loading - because hot material works easier than cold material, and it annealed it from the last step. Once the tubing "billet" got over about 50' to 60' in length and about 2" in diameter the process reverted back to much more like wire drawing unless they were processing straight hard copper tubing, in which case the mandrel mounted dies remained in use. Which is why the ID of hard copper is so much more precise than soft copper. Soft copper was processed almost exactly like wire - except it wasn't drawn thru by routing around pulleys they used a lot of traction drive wheels.

I didn't get to see it happen, but my interviewer told me that it would really foul up the works for a while if one of those die button mandrels got bent or broken.
This particular company also had their own patented continuous casting operation that cast the original 11"-12" diameter billets - which started out about 22 foot long as I remember, and cut these to process length right before being induction reheated.

PS I've met some of the people at Baekart and other companies in the past - Over the years I attended 3 or 4 of the International Wire shows when it was in Atlanta. Though the last time was probably in the early 90's.
 
Last edited:
thanks vibe. i think i under stand. in your tubing description the die button and mandrels would be like the button and rod used for button rifling. if the button gets nick or scratch in it the barrel is flawed(naturally) and if the mandrel it is on gets bent the barrel is flawed(naturally). that is very understandable. now can you link this with barrel diameters and tuning? we could be getting someplace now.
 
thanks vibe. i think i under stand. in your tubing description the die button and mandrels would be like the button and rod used for button rifling. if the button gets nick or scratch in it the barrel is flawed(naturally) and if the mandrel it is on gets bent the barrel is flawed(naturally). that is very understandable. now can you link this with barrel diameters and tuning? we could be getting someplace now.
Hmm. Are you suggesting that in all of the lands and grooves are not EXACTLY identical, in both width and depth, that this is a source of inaccuracy? To what level of precision? As this is the "flaw" that your examples would create.
 
Last edited:
if the button is nicked or scratched then there would be those extra places put into the barrel to corespond to those nicks or scratches yes. and if the mandrel was bent wouldn't that cuase the button riding on it to be at a angle as well, so that would make the depth of the grooves different as well? i don't believe any amount of lapping would be able to fix a flawed barrel like that. much like the mandrel in the tubing you spoke of. if not found and replaced it could make alot of bad products.i could be wrong but lead on vibe.

i hope i get this edit done before you can respond, but in this process we are speaking of there is always wear on the buttons/dies. this will cuase in the tubing and barrels a tighting of the bore. if not cuaght and replaced again there could be bad products made. i know in wire drawing the dies start out just a little close to the undersize of the spec for the wire so that they can get more out of it before it goes to oversized. would they start out with a button maybe close to over-sized so that they get producion before it is undersized in mass produced tubing and barrels?
 
Last edited by a moderator:
so what are you guys saying???? the person who invented the first tuner, a fellow by the name of Shapel back in 1954-1957 did he work in a wire production plant? or doesn't working in a wire production plant have anything to do with a tuner?????
 
if the button is nicked or scratched then there would be those extra places put into the barrel to corespond to those nicks or scratches yes. and if the mandrel was bent wouldn't that cuase the button riding on it to be at a angle as well, so that would make the depth of the grooves different as well? i don't believe any amount of lapping would be able to fix a flawed barrel like that. much like the mandrel in the tubing you spoke of. if not found and replaced it could make alot of bad products.i could be wrong but lead on vibe.

i hope i get this edit done before you can respond, but in this process we are speaking of there is always wear on the buttons/dies. this will cuase in the tubing and barrels a tighting of the bore. if not cuaght and replaced again there could be bad products made. i know in wire drawing the dies start out just a little close to the undersize of the spec for the wire so that they can get more out of it before it goes to oversized. would they start out with a button maybe close to over-sized so that they get producion before it is undersized in mass produced tubing and barrels?

Cannot speak for every maker of button rifled barrels but your guesses about button damage are just that guesses. 416-416R is soft and most of these buttons are carbide and don't scratch, they shatter. Also a bores straitness is largely going to be determined by how it's drilled and reamed, after that whatever is pushed through it is going to follow the hole that's there. The final size of the bore is also going to be largely dependant on the drill, reamer sizes, assuming a maker has been around long enough not to lap the lands out of a finnished barrel which the good ones generally do not. This stuff typically ends up being some version of "if we had some ham we could have some ham and eggs, if we had some eggs".
If you ever are able to go to a barrel shop, go, although it is usually about as had to get into the pentagon when rifling is being done.
 
Last edited:
so what are you guys saying???? the person who invented the first tuner, a fellow by the name of Shapel back in 1954-1957 did he work in a wire production plant? or doesn't working in a wire production plant have anything to do with a tuner?????
what? wait a minute i looked it up you're right. here's the article, when here i thought
it had been invented in 1994. and it was even patented then in 1957 before browning.
http://www.highbeam.com/doc/1G1-16119231.html
 
Tomc, have you ever tried tuning in December? that's one reason I thought the story was another made up out of the blue story. it makes sense in june of 54 when everyone's outdoors shooting, anyone trying for the first time to tune in december would face Hugh obstacles we now know. saying you discovered a tuner in december is another myth.
 
Tim,
If you go to one of our Shilen Swap meets. The guys run the machines as a demonstration for the unwashed public. Put your hand on the barrel while the button is drawn through. You can feel the button when it passes your fingers.
Butch
 
what? wait a minute i looked it up you're right. here's the article, when here i thought
it had been invented in 1994. and it was even patented then in 1957 before browning.
http://www.highbeam.com/doc/1G1-16119231.html

Which is why I've often maintained that Browning bought (or bribed) their way into the BOSS patent. By patent rules the BOSS should not have been different enough from the "prior art" and public practices to be "patentable".
 
Dang i learned about words i don't hear every day they flow real good when put into a sentence. anyone else scratching their noggin.
 
Which is why I've often maintained that Browning bought (or bribed) their way into the BOSS patent. By patent rules the BOSS should not have been different enough from the "prior art" and public practices to be "patentable".

i agree, it's like if you take a set of racing tires for a car and put them on a truck, it's still a set of racing tires. same as rimfire and centerfire, a rifle is a rifle main difference
is the type of ignition system.
 
Back
Top