Thank you for asking these questions Fl-flinter. I wondered myself why Stress Relieve Anneal, and subsequent Electro Magnetic processes seemed to have been avoided in the previous discussions on the two threads (Douglass Barrels and this one).
R
You all may need to go back and read the LaSalle letter again where he specifically states the the various cold rolled free machining steels list are not suitable. His comments on heat treat were for other steels and do not apply to cold rolled.
It is impossible to make relatively low quality steel with high levels of sulfur/lead/phosphorus "safe" by heat treatment. This will not remove the inclusions or flaws in the steel resulting from the way it was originally made for its intended application.For those of you who feel that all modern guns are made in a safe and sane manner I would point to the wide spread use of 416 and 416R stainless. (SAKO had a number of failures and recalled guns, there have been other failures as well but this is the only recall I know of) and Kreiger does not recommend their use under 0F. It too is a free machining material.
So why do they make them? Because people want SS barrels and actions.
I have no idea what the hammer forging process entails but I suspect that the barrels are stress relieved afterwards. Its not done because its the best way to make a good barrel its done because its CHEAP in the long run and not very labor intensive.
I do know that button rifled barrels made of hot rolled GB quality steel must be annealed afterwards or the bore dimensions will be lost when the barrel is machined to contour.
1137 is not my first choice for barrel steel. But its a
long way from my last choice. I do know that I have never heard of one blowing with BP and there are LOTS of them out there in calibers that will make 30000 psi with BP. The 45-70 factory loads, the HV ones, are limited to 28000 by SAAMI. I know from lab tests that the barrels will stand 50K with no stress at all in 45-70.
The ones that blew were used with smokeless and were SERIOUSLY overloaded and simple over pressure does not fragment the barrel so I have a lot of confidence in 1137 for ML barrels. I would rather have 4140/50 which is the Gold standard (it will stand cartridges in the mid 65000 range) but its tough to find people who make swamped ML barrels in this alloy and grade.
So people worrying about overloading and harming an 1137 barrel with double powder/double ball frankly don't know what they are talking about. The proof load simply will not make enough pressure to cause a problem if the barrel is sound. It its not sound? Well thats what the proof load is supposed to find out.
A friend, who also used to work in plant that made barrels, told of a recent conversation with an ICON in modern match grade rifle barrels. He stated he would prefer skelp welded wrought iron barrel to leaded screw stock which he would not pull a trigger on.
I suspect that there was a reason why the US gov't staid with iron for barrels until the cartridge era. Steel making was hit or miss and the alloy was not really known. It was either mild steel or high carbon. A really good iron would be more suitable when the alloy is not known. Note that the "stronger" steel barrels used on MLs in the 19th century were often heavier is cross section than the older iron barrels. Could have been the advent of the percussion system or better powder or the use of the picket bullet. But the guns got heavier it seems. Except the Gov't iron barrels. The Minie rifles were still pretty light in the barrel and stood serious proof levels from what I have read.
I used to work in a place that makes button rifled barrels. The failure rate (splitting) in buttoning hot rolled GB quality 1137 or 4150 is low. I remember 1 maybe 2 in several years the one I specifically remember looked OK externally but had a full length crack in the bore that the button had forced the edges into then when the crack closed again it squeezed a ridge up in the bore. The failure rate when doing barrels in mill run 1144 "Stressproof" was over 10% if the barrels are rebated at the muzzle as this lot of barrels was.
Which would YOU prefer to have next to your face?
I walked back to the big old broach they used to pull the buttons one day and saw a number of failed (read cracked open) barrels and then looked at the paint color, checking the chart in the tool room told me that it was stressproof.
Now you might ask why were they made of this?
The plant owner bought what he could get. One of his arguments was a
classic "its a 100000 psi steel". Again the belief that the TENSILE number means something. In this case it does not and is actually misleading.
He bought it BECAUSE SMALL LOTS OF GUN BARREL QUALITY STEEL CANNOT BE OBTAINED unless the maker can find someone with an excess and this is not likely.
Its tough to get it in semi-load lots. It has to be ordered, it is then made in the bar sizes ordered.
But it has to be bought by the FURNACE LOAD. So "small" makers of premium barrels end up pooling their orders to get enough tonnage to justify the mill making a run of the stuff. This is hot rolled 4140-4150 GB quality. Its also expensive.
But anyone can buy Stressproof by the bar. Its mill run and they make it in large batches with just enough care to make sure its meet the alloy requirements and has enough lead and other lubricants to machine easily. They don't certify anything or take any care to make special QUALITY STEEL.
My belief that Douglas annealed some late production ML barrels was based on the fact that the later ones had a hard scale much like hot rolled steel. The people who ran into this stuff, gun makers, decided the hard scale was from heat treat before the bar was made into barrels.
I don't know of anything that would produce this other than hot rolling or some heat treat after the bars were made.
I would not equate the gun barrel makers not quenching and annealing GB quality steels after all machining processes are done with the practice of using low quality cold rolled steel for barrels. Its apples and oranges.
The proponents of using leaded screw stock for gun barrels spend a lot of time attacking the fringes but will not address the specific statement that the company that INVENTED Fatigueproof and Streesproof (they are niether BTW) specifically states they should not be used for gun barrels. When confronted with this they simply say the guy does not know what he is talking about.
AS I PREVIOUSLY STATED:
THE LETTER IS FROM LASALLE STEEL. ASK THEM WHAT THEY MEAN. I just passed on the info and have no way to try to interpret what they may or may not mean.
Somehow people see someone pointing out that some modern made breech in not safe, for example, as a personal attack since they own one I guess.
This is not the case. Its simple fact. If the breech, for example, does not protect the shooter from being struck by cap fragments for example the breech is not properly made. And this applies to some high quality vintage guns as well. Its not as though its a new problem.
But when people perceive some insult or attack all comprehension goes out the window.
Unless personally attacked I will not be posting to this thread again. The primary reason for posting most of this is two fold, to pass on what I have learned over the decades and hopefully get people to think and DO THEIR OWN RESEARCH. But in my experience its hard to find a metallurgist to go on record where gun barrels are concerned. The last time I tried to find one (back when the Stressproof barrel blanks were splitting) I had to get a friend to contact a friend who knew a prof who was the head of Metallurgy at a eastern University. I got back a one line question: "Why would anyone use anything but chrom-moly for gun barrels?"
By the time I left the gun factory they were using GB quality 4140/50 chrom-moly for all barrels
And one more thing. There is another purpose for posting safety related material. It allows people to make an INFORMED DECISION. I only brought up the unsuitable material because the topic was proof and its impossible to proof unsuitable material. The things that make it unsuitable (see the LaSalle letter) mean that proving it is meaningless since it has properties that can cause it to fail after proof or with not proof at pressures far under a proof load. From where I set at the computer I can see 3 guns with Douglas barrels. A rifle and a pair of pistols. I have retired the rifle until I rebarrel it. I have retired and then used this rifle a couple of times. But I just can't justify it anymore. I have Green Mountain barrels I can shoot. The pistols (and the rifle for that matter) are collector pieces anyway, but I have a GM out in the shop for the rifle. Will set the Douglas in the gun safe for posterity.
I have another rifle with a screw stock barrel that I really hate not using. But I have a line on another barrel maker who does not use screw stock who might be able to make this somewhat oddball. Or I might get a couple of pieces of Chrom-moly from the gun factory, ream and try rifling them...
Dan
