Once again Dan, you're jumping all over the place without any direction and have yet to make a valid fact-based point on anything. I'm not trying to be rude man but you come out guns-a-blazin' yet you want to have things both ways.
A while back you made a big fuss over how conical bullets in a ML produce too-much pressure then today you turn around and say that a .45x3.25 can't be blown-up with smokeless. Two days ago you said, "Its near impossible to generate pressures with BP that will even remotely reach the operating pressure of modern sporting cartridges some of which have a normal pressure of 65000, 4140-4150 will safely contain these pressure levels. BP simply will not make this pressure or anything like it when used with a projectile. They were able to get 100000 for BP ONLY in "closed bomb tests" i.e. a sealed chamber." Then you go on to claim that "mild steel" is being used for smokeless barrels and back in the day they couldn't blow-up wrought iron/forge welded barrels with massive charges yet today we have to use some special alloy yet you can make the distinction between how a finished stock shape is made and what affects the properties of the said stock.
Let's start with your constant reference to "cold rolled". First off, the "cold rolled" is a reference to how the stock is formed, yes the process affects the properties of the stock AS-FORMED, the materials working properties can, and are normally, changed by various heat-treating methods that occur POST-FORMING. Cold rolling is mere a method used to maintain tighter tolerances on the finished stock - thus is why common shapes are often listed with options such as: As-rolled; Low-temperature normalized; High-temperature normalized; Fully annealed; Half-hard; Full-hard... It is the post-forming heat-treatment that gives the finished product it's working properties such as is the case with a particular alloy that will vary from 7% to 15% elongation at break solely dependent on the heat-treatment process and it doesn't matter if the alloy is cold-rolled, hot-rolled, hammer-forged or cast to shape. If you're so hyped on "cold rolled" why do you shoot modern cartridge guns that are button-rifled which is no different than cold-rolling since the button is pulled through the tube with enough brute force to cold form the rifling?
If, as you incorrectly claim, black powder cannot generate excessive pressures under a projectile, why then do you even worry about so-called proofing to begin with? Also, if this is the case, why do you constantly harp on danger of improperly sized/loaded conical bullets sliding off the powder? Furthermore, whenever anyone brings up shooting conicals from a ML, you immediately fly off the handle yapping about "excessive pressures" and "nipple wash-out" but in this post you claim an over-charge of smokeless under a heavy conical in a sealed cartridge rifle is a perfectly safe endeavor. Perhaps you need to have a chat with an acquaintance of mine from McAdoo, PA so he can explain to you how the breech section of an 1137 alloy barrel fragmented with a mere 80gr charge under a .50 PRB that got hung about on the crud ring about 3/8" above the powder column - GM drop-in IBS. Granted, self-admitted operator error but that doesn't change the fact that the 1137 fragmented.
While you're so hyped on harping about alloys, let's address your claim about 4140-4150 safely containing 65,000 psi - what happens if that same 4140 or 4150 was heat treated differently? Ever consider that it can be treated in such a manner that it will come apart in a big way with a mere 32,000 psi. Here's an example of improperly heat-treated 4140
Here's a heat-treating issue with 416 stainless
Two failures, both caused by improper heat-treating ... what point does it prove considering the millions upon millions of guns built from 4140 & 416 that are out there functioning just fine day after day - if 416 was such a safety issue as you seem to claim, don't you think gun mfg's would have stopped using it years ago? Truth is, no matter what the alloy, they're all prone to failure if the alloy is bad, if they're built wrong or if they're abused. Remember all the hype over the low-S/N 1903 rifles? It wasn't a problem with the alloy, it was a problem with heat-treatment and therefore your attempt to make an argument out of alloys is moot. How about that precious 1137 for instance? Depending on how it's heat-treated POST-FORMING, the yield strength can vary from 46,300 psi to 87,700 psi likewise, the particular heat-treatment varies the elongation at break from 10% to 23.5% Asking the question "So what it (sic) the "proportional limit" of 1010 or 1020 in thin wall barrels?" is pointless because the proportional limit for the given alloy not only varies according to the stock thickness but also according to how the particular alloy is machined and heat treated. I freely admit that I am but a mere novice on this and I know one of the metallurgists who frequent this forum could explain how post-forming heat-treatment affects alloy properties a lot better and in for more detail than I can. What I can tell you is that I have more than a couple decades of doing things that everyone else claims are "impossible" and there's no "magic" involved, just a learning about and understanding what you're working on.
What I can also tell you is that the heat-treatment is all-critical to the operational performance of the alloy. Weld on a modern alloy truck frame with the wrong filler alloy or don't properly heat-treat the entire area post-welding and it's going to break. How about seamless tubing? Ever wonder why some people have gotten away with using it for years and others end up in the ER? Here's a couple pieces of the same exact cold-rolled seamless tubing put to a hydroshock test:
Note the distinct difference in how they failed and understand the only difference between them is how the tube was heat-treated post-forming. It's the same like the people who got on the "T1" kick for building truck/trailer mounted dump bodies, no attention was given to the particular post-forming heat-treatment of the alloy and the majority of those bodies looked like post-fall Humpty Dumpty within a year ... the same with those who insisted on using 5356 wire to repair aluminum in high-shock/high-flex applications then wonder why it kept failing ... and the same as the ignorant who insist that using E-12018 electrodes to join mild alloy steel will make the joint stronger then wonder why the weldments continued to fail over and over again.
You can spout about this or that "alloy" all you want Dan but until you understand that the alloy number does not necessarily represent the actual working properties of particular piece of stock made from that alloy, you'd be best served not making such generalized statements. I would think as a "breech loader maker" you would have some concept of how heat-treatment can greatly vary the properties of an alloy ... but, then again, I've seen graduates from the CO gunsmith school who don't know which way to move the front sight to change the POI. Tell me Dan, are you willing to work with a suspended load on 200 ton hydraulic truck crane that some schmuck allegedly "tested" by trying to lift 400 tons with it? Are you willing to work with a 175 ton load on that same crane if the spreaders were made from an alloy that wasn't properly heat-treated?
I feel compelled to respond, though I am sure I will regret it
If BP will generate such high pressures behind a projectile why are velocities so limited with BP?
If it will generate 50000 psi or even 40000 (357 magnum pressure level) why is it necessary to use smokeless to make over than 2000 fps with anything but the lightest projectiles? How heavy a projectile does it take to get a 45 caliber bore to 40000 with BP and how much powder does it take?
You claim it will make high pressures with projectiles. Where is the data? Have you pressure gun data showing BP making 40000 of 60000 psi in a barrel with a projectile in front of it?
Wrought iron, GOOD wrought iron, properly welded. Is an adequate material for BP barrels for muzzle loaders this has been well proven, its better than some modern steels regardless of its lower paper numbers. But it IS weaker than a suitable steel so a modern steel approved for and made in a quality level for gun barrel use by the steel maker is better.
The problem with wrought iron, back in the day was the quality thing, kinda like some steels today. The circa 1860 Springfield Rifle Musket barrels were made of best grade iron and carefully welded and formed. Then heavily proved. A barrel made an PA gunshop in 1770 from the typical iron of that time is far more suspect. Look at the quality of iron found in trade gun barrels in the 19th century. Far too many inclusions. So one cannot paint all iron barrels with the same brush anymore than one can do the same thing with all steel barrels. That steel barrels were considered better than iron by the 1860s is pretty obvious but the Springfield barels were adequate for the minie ball and people trying to blow them up in the 20th century, SFAIK, failed. Thus the "you can't blow up a ML barrel" myth was born.
Conicals in MLs provide a number of problems that are not present in cartridge guns. I will attempt to explain.
For example the cartridge guns don't have leaded screw stock barrels, they don't have nipples to gas cut and blow gas and cap fragments in peoples faces and the bullets are not likely to slide away from the powder and produce a bore obstruction and burst or bulge the barrel.
ITS APPLES AND ORANGES due to these factors alone. Then we have the abysmal exterior breech designs of most Wal Mart specials (an others), drum and nipple guns....
Its not ALWAYS the barrel that is the limiting factor. There were and are ML arms that people shot/shoot upwards of 120 grains of powder and 3 caliber or longer bullets for 1000 yard competition. BUT. They don't carry them around hunting so the bullet can move, they (hopefully) don't have free machining leaded steel barrels, the Italian Gibbs repros, the premier none custom repro for long range right now use real barrel steel from all reports and the originals use hot rolled or high end Damascus (its as strong as any other 19th century barrel material and stronger than most) and they tend to use good locks and platinum lined nipples. To compare these rifles with the typical coil spring lock Wal Mart special ML is silly.
Free machining cold rolled steel cannot be magically made into gun barrel quality steel by a heat treatment. It can be IMPROVED by a complete anneal and quench and the annealed again this will make it less brittle. But the QUALITY LEVEL can't be changed. So the excess sulfur and/or other metallic compounds used in free machining steels to make them easy to machine and cause INCLUSIONS IN THE STEEL THAT WEAKEN IT FOR FIREARMS USE (they are problematical to weld for the same reason) cannot be removed by any process available after the steel is made. The inclusions may well make the steel respond to pressure containment in a brittle manner but this is metallurgist territory.
So if you have a bar of 11L37 cold finished mill run steel or a heavily sulfurized steel that has these things added to make it machine better an anneal/quench/anneal will not remove the the inclusions. It will make it less brittle, but its still not gun barrel quality and might not be suitable as pressure containment.
The burst guns, wonderful photos BUT THE RIFLE IS NOT 4140 (ROTF) .... ITS STAINLESS ... Look a little closer.
416 stainless is a free machining, brittle, stainless. Look it up. A number of stainless bolt action rifles have had UNEXPLAINABLE catastrophic failures with FACTORY AMMO. Sako recalled a BUNCH of guns a few years back because they got a "bad lot of stainless steel" (you posted a photo of one of the blown guns). But apparently they passed proof if Sako is subject to proof laws. Both the burst firearms are classic brittle fracture. A couple of years ago I would have labeled the handgun as a classic undercharge burst but given the things that have come to light about 416 its likely the material.
Do you THINK the makers are going to admit they have guns out there made of material likely to burst when the failure rate is low? Its cheaper to deal with the burst guns. Heck Remington never had to recall the 1140M barrels that they lost the court case on. So recall? Ha!
Note the statement concerning low temperatures and reprofiling stainless barrels here.
http://www.kriegerbarrels.com/Calibers__Prices-c1246-wp3390.htmIts at the bottom of the last table on the page.
Real confidence builder for the Stainless owner living in AK or any place else much north of Memphis.
Here is an excerpt from a post by a mechanical engineer at
http://forums.1911forum.com/showthread.php?t=187083&highlight=barrel+steel+alloy ******
As you already know from our earlier conversations, I'm not a fan of any alloy not approved by the ASME for pressure vessel use, i.e. barrels. I'm well aware of the 416R alloys. Last I checked with the ASME, NO 416 alloy was approved for pressure vessels. So unless 416 has been recently approved by the ASME, I don't use it. Regarding 416R; reducing the sulfur content in 416 alloys is only part of the problem. Both sulfur and selenium in the 416 alloys form stress concentration sites in the material which reduce the fatigue life and fracture toughness. Result? Early cracking and catastrophic failures in 416. The ASME testing program, to approve pressure vessel materials, are very, very thorough and brutal. Hundreds and hundred of professors and scientists run exhaustive tests on these materials before acceptance is finally awarded by the ASME. The ASME got into doing this after the U.S. Congress asked them to help in eliminating pressure vessel explosions. I am, as a Mechanical Engineer, very familar with this ASME testing. Finally, in my view, if your interested in using stainless steel 45 barrels, use the Wilson 17-4PH barrels. They're excellent in quality,high strength and toughness.
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I never said the BPCR overload was safe, you read that in. I said it would not have damaged the shooter, probably an error, the recoil would have been fierce.
But the rifle was not damaged with all the 4198 that could be put in the case UNTIL THE BORE WAS PARTLY OBSTRUCTED. But alas the barrel only split in a non brittle manner it did not fragment. The difference here is I had conversations with the guys that did this and looked at the resulting damage. So I am not out in fantasy land. While its not a scientific lab test its still useful information that does not require referring to cranes and rock boxes.
The fragmented ones were the ones burst by owners shooting
light loads of IMR smokeless. Boy did one guy bow one up with a "BP duplication" load of 3031.
After I talked on the phone for 1/2 hour plus telling him he was going to blow the gun he did as he wanted anyway and fragmented even the receiver but shooting from the bench with his non-shooting hand behind his right elbow he was uninjured. So yes its possible to blow up a 1137 barrel and 4140 receiver with an IMR powder if one works hard enough. But I knew that BEFORE HAND. It was written up in the 1930s when the IMR powders first came out. You can find this in Phil Sharpe's Guide to Handloading.
The fragmented 1137 ML barrel? Had the barrel been proved? I bet not. Remember my comments about gross flaws? This is why guns should be proved, Then... Look at the burst stainless barrels you pictured? If Sako or Colt can get "bad" steel so can GM. To me the ML failure is an argument for proving ML barrels. The Sako and Colt are an argument for using a PROPER MATERIAL for firearms. Though 1137 is not my first choice even for barrels just because its not the best choice, its long way from the worst choice.
Mild steel 45ACP barrels. Here is a list of parts for sale in an old post on the 1911 forum
Does not mention alloy but the two part barrel is mentioned. I did the red highlight so you could find it easily.
http://forums.1911forum.com/showthread.php?t=36957&highlight=Springfield+Armory+barrel+steel************
Parts from Springfield Armory Milspec, parkerized.
All parts are from new unfired pistol, taken off from gunsmith buildup of base gun.
-2 piece SA barrel with link, pin, bushing-milspec grip safety
-SA ILS mainspring housing, arched serrated, complete, with 2 ILS keys and tool
-trigger, steel, short
-slide stop
-mag catch (without spring or lock)
-recoil spring
-hammer
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Heat treat.
Any fool can screw up the heat treat and break a piece of steel. This does not make the alloy unsuitable or dangerous for a given application, this is straw grasping. The idea of someone making a barrel from a piece of quenched but untempered steel is a stretch. So its not likely that a barrel this hard it going to make it one a firearm. If you have ever machined 4140 you know that its a lot easier when its properly annealed and even better when cryoed.
So unless you can find a blown up 4140/4150 barrel (actual 4140 this time not stainless) that was so hard it shattered because someone heated it to critical temperature and quenched it after it was a made into a rifle barrel give up on the "possible" scenarios.
Anything is possible but its easy to let yourself slip farther from reality in doing this so you might want to stay closer to fact than fantasy to bolster your position. The crane/welding truck frame thing gets pretty far from firearms applications. Fortunately we don't weld on gun barrels, at least I hope not.
The guys that go to gunsmithing school know things I do not but I know things they don't teach there, at least not from what I learned working with one or two such for a year or so. Moving the sight the wrong way? Everyone will do it at sometime if they do it enough. I am fairly well versed in this and did it on Dad's Remington a few years ago. Besides for moderns iron sights are pretty old school now.
Barrel steels have been an interest of mine since the big fight erupted years ago in the Buckskin Report though I am certainly not a metallurgist or mechanical engineer I know what is not supposed to be used. A lot of guns were failing at the time and the reports were making it to the publishers desk and he was interested. Most were from people shooting Maxi-balls in Wal-mart specials and even cheaper copies of Wal-Mart specials. Some even used smokeless.
If you did not read the letter from LaSalle Steel (they developed the material IIRC and trade marked "Stressproof and "Fatigueproof" (12L14) but neither is either when used for gun barrels) you might want to search and find it. I think I posted it on this site at one time or another. But what would they know? They never made a ML barrel. (More ROTF laughing)
Dan
