Dan Pharris,
There's a lot of discrepancies in your statements that need to be clarified and you didn't directly answer any of the questions I posed. I'm not arguing alloys; people who use nitro powder in a muzzleloader; people who don't pay attention to what they're doing when loading; people who partake in the stupidity of "speed shooting"; people who don't know how to properly load or anything else. I'm "asking" you to answer to the following questions based on the information and statement
you provided in this forum.
The LaSalle letter, item 4 concerning "Gun Barrel Quality" steels states that
"A thermal treatment after all machining and fabrication operations which will assure complete recrystallization of the material. Only a full anneal or quench and temper operation will fill this need."
1- Would you please explain what type of thermal treatment you give your barrels when you're done working on them and what process do you use. On numerous occasions you stated that you use high-temperature silver braze to attach accessories to the barrel ... I'm asking if you again do a complete thermal treatment on the barrel post-brazing since you changed the properties of the barrel, at a minimum in the heat affected zone, during the brazing process?
2- When you make your breechplugs, do you heat-treat the plug itself as a separate piece or do you just heat treat or anneal the entire barrel assembly after the plug is installed and all other work is done?
3- The Buttress style thread is the strongest thread design, it is used on large artillery gun breeches because of its superior strength so why is it not used on small arms?
4- When you install the breechplug, do you adjust it to a known torque value or do you use a compression formula based upon contact with the boss & face? Also, what formulas do you use to determine said torque or compression rating and do the formula(s) take into account thread engagement loading strength based on contact surface mapping of the actual assembly or do you use assumed constant values in the calculations?
Related to this question is your statement about "sealing the bore":
A friend built a lot of guns using bolts for breech plugs. They are made to a specification. The taps used are made to the same spec.
There will be a certain amount of slop in any threaded joint. If that worried about thread fits. The standard fit is 75% IIRC, then make your own breech plugs so that the tolerance can be controlled. But the fit is not THAT critical if the bore is sealed.[/u] Re: powder chamber on breech plugs « Reply #35 on: December 18, 2010, 01:38:12 PM »
I'm curious to know your secret on "sealing the bore" with a breechplug when there's no intermediate gasket material involved. I've worked on a lot of stuff and any time you have a connection with non-tapered threads, some type of additional gasketing material is required to achieve a "seal" between iron-base alloys. Looking at the breechplug fitting pictures you posted, you're showing the steel plug mating to a flat steel boss in the barrel breech - in the above quote you stated that the amount of "slop" in threads isn't really critical if the bore is sealed ... my questions are:
A- How do you achieve the alleged "seal" and how do you test the seal? I'm curious as to if you pressurize the bore to 20ksi or so with nitrogen or what ... there has to be some form of bench testing you use to establish the quality of the "seal" - I mean it's impossible to perform any kind of "seal test" using powder burn because the massive volume of fouling generated by the burning powder would create a false positive.
B- The threads that are retaining the plug and therefore the thread strength is critical to maintaining the alleged seal - thus, if the threads fail will not the alleged seal be compromised as well? How does the alleged "seal" prevent mechanical strength failure of the threads?
C- In other threads you claim a certain breeching style is "the strongest" but the accompanying drawings show the vent liner penetrating the load-bearing threads of the plug - please show the engineering data that proves why that particular breech style is allegedly "the strongest" and how one achieves a stronger threaded breechplug connection by removing a portion of load-bearing threads on the plug joint.
5- Can you please explain the difference between a bar of steel that is cold-rolled and a modern gun barrel that is formed by cold-rolling or cold hammer forging? I ask because in another thread you said that rolled threads were stronger than cut threads however the thread rolling process is done cold ... and if you're cutting threads in the breech or on the plug, are you not making a weaker connection and should therefore seek out barrels and plugs with threads that are formed in a cold-rolling process? Reference your statement:
Bolts have rolled threads which are much stronger than cut threads. Re: powder chamber on breech plugs « Reply #32 on: December 17, 2010, 10:56:51 PM »
In this thread you stated:
I have no idea what the hammer forging process entails[/u] 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.[/u] Re: To proof or not to proof a barrel. « Reply #53 on: January 21, 2011, 11:38:36 PM »
If you don't know what the hammer forging process is as you claim in the first sentence, how can your very next sentence be presented as a statement of fact condemning hammer forged barrels? Would you not need to have at least a basic working knowledge of the process and outcomes in order to make the statements you did in the second sentence of the quote above? Sorry Dan, that's just confusing when you say you don't know anything about X but in the very next sentence say with absolute fact that X is bad ... doesn't make sense to me and some clarity would be in order to explain your conflicting statements.
And, can you please explain the difference is between forming steel stock by cold-rolling and making a nitro shotgun barrel using a cold-rolling process? Again, I'm asking for clarification on your conflicting statements because it's just not making sense to me that you praise cold-rolled bolts as being superior in strength to a machined fastener but then make the statement that anything cold-rolled is inferior to something that's machined.
Need some clarity on this statement too Dan:
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. Re: To proof or not to proof a barrel. « Reply #53 on: January 21, 2011, 11:38:36 PM »
You lost me on that one Dan ... Are you saying that gun barrel makers don't heat-treat after all the work is done, and if so, does that not go against what is clearly stated in number 4 of the LaSalle letter concerning gun barrel quality steel that clearly states the barrel must be heat-treated after ALL work is done? Is your second sentence implying that all cold-rolled is low-quality or are now making the distinction that there is a difference between "low-quality cold-rolled stock" and "high-quality cold-rolled stock"? Not arguing, just asking you to clarify your statements.
6- After you overcharge the barrel and it doesn't blow up, what inspection method (IE: X-ray, ultrasound, eddie current?) do you use to ensure that the overcharge did not cause internal fracturing or some other problem that may result in a failure at a later date with a normal service charge? What pressure testing equipment do you use to show that your alleged "proof load" did not exceed the proportional limits of the barrel assembly?