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Denton, You're a smart guy. We seem to go round and round on this subject. Maybe this can never be resolved, like liberals and conservatives, but maybe it can. If there were a matrix of the possible techniques, with pros and cons for each, maybe we could stop fighting over non issues. | ||
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I believe use of a chrono while working up loads is the best sign easily available. But any 'signs' should be 'heeded' from bolt lift to primers, strain, ,PRE/CHE, etc. I could be wrong but at excess pressure, whatever that is, one probably won't get good accuracy, barrel life, or case life. Best-o-Luck | |||
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Quote: Well said. | |||
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Quote: Hey belaw, Yes to the first question. And you have hit on the crux of the point with your second question. No, it makes no difference at all if the Reloader knows the actual Pressure, just that it is a SAFE MAX Load or slightly below SAFE MAX. We simply let the Ammunition Manufacturers set the Pressure Limit with their Millions of Dollars worth of Pressure Testing Equipment, observe the PRE "they established", and then STOP adding Powder when we reach the same PRE with our Test Loads in the same cases. As simple as that is to understand, there are some folks who are totally unable to comprehend how that works. There are a few "techniques" that enhance the ability to get good, accurate CHE/PRE readings that I'll send you if you would like them. The problem with the HSGS fiasco is a total lack of accurate data. Obviously "you" will be able to understand it is impossible to get usable, accurate data from a device that you have to "guess" at the absolutely critical Set-Up dimensions and which is impossible to Calibrate. Not hard at all to understand why the HSGS is nothing more than Reloaders Pyrite. Quote: Factory ammo to establish a Benchmark Standard for the PRE. A 0.0001" capable Micrometer to do the measurements. (A Blade Micrometer is also REAL NICE to have if you have Rimless and Non-Belted cartridges to measure the CHE.) A Load Data Sheet to track what you load and the CHE/PRE measurements as you fire the Test Loads. An eye for detail as you handle the cases. A Primer Pocket Uniformer which can tell you on some of the "higher Pressure" cartridges if in fact the Primer Pockets are getting shorter. Primer appearance which is difficult to explain due to the subjective nature. Sticky Bolt lift and/or Ejector marks which means you really need to back off the Load. Depending on "how it is used" a chronograph can provide some information, but it can be totally misleading. Since it can be misleading, I rarely recommend wasting money on one. Most "Clubs" own a chronograph which the Members can use. Quote: I'd recommend that you don't put yourself down for realizing the obvious. As you can easily see within this thread there are folks who believe in Fool's Gold! Earlier today I was flipping through P.O. Ackley's 1962 2 Volume, "Handbook For Shooters & Reloaders". Somewhere within one of them Mr. Ackley was commenting that information contained within any Load Manual is basically Reference Material. The load shown "only applies" to that specific barrel, with those specific components, and fired under a specific set of conditions. He also recommended using more than one Manual to get an idea of what a cartridge "might" be capable of and then watching closely for Pressure Indicators. A lot of the information in Mr. Ackley's Book is seriously dated, but that information is as valid today as it was back then. | |||
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Quote: Hey Clark, I didn't realize "you" were fighting the issue! Oh, thats right, you use the Extractor Groove Expansion Method - basically got your Groove on!  As long as we have people recommending totally BOGUS Pressure Detection Methods when they don't even understand the """CASE""" is the weakest component in the Firing Sequence< !--color-->, I'll go waaaaaaaaaaaay out on a limb and "Predict" - The ignorance will continue. As for a reference that some of HSGS folks have(had) ZERO comprehension of this absolutely basic Rookie Reloader level fundamental, I'll let them tell you in their own words: Quote: How `bout a Group DUUUUUUUUUUUUUUUUUUUUUUHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!! (Please play the Carny Music in your mind while reading the "sure to follow" totally irrational response! Old PT Barnum would appreciate it! ) | |||
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HotCore & Travis, With CAREFUL / PAINSTAKING SET_UP AND UTILIZATION OF A KNOWN CALIBRATION STANDARD (HYDRAULIC PRESSURE WORKS GOOD) a strain gage system can provide fairly accurate measurements in PSI (once all the necessary math is done). Unfortunately, I have found the the bold faced caveat at the beginning of this post is VERY difficult, if not impossible to do on a STOCK sporting rifle barrel. I have a heavily modified barrel that I could post pictures of, to illustrate what really needs to be done if one wishes to get accurate measurements into the 100s of psi, but I am afraid someone would attempt to copy it and blow themselves up! So I shalt post a picture, and please don't ask. Having said that, if one is EXTREMELY precise in one's set-up on a stock sporting rifle barrel, one can get to withing 1500 psi of reality, I believe. However, this degree of expertise is not for the novice, and probably is above 99% of reloaders capabilities, (due to a myriad of factors, not necessarily skills or desire gentlemen). For instance, believe it or not, the surface finish on the barrel has a HUGE effect on the accuracy of the reading. Also, since the pressure is a based on a calculation from the measured strain (resistance or millivoltage to be precise) the axial position of the strain gage is very important, as well as, its position radially around the barrel (one must align the strain gage to measure either hoop or axial strain, they are 90 degrees apart, sloppy set-up VERY EASY TO DO, will mix the strains and provide erroneous output from the math model being used to calculate a chamber pressure). Anyway, enough beating a horse, live, dead, or comatose. All the systems have the limitations. The important thing, in my opinion, is that the end user of any of these systems CLEARLY UNDERSTAND THE LIMITATIONS OF THE SYSTEM THEY ARE USING AND LIVE WITHIN THOSE LIMITATIONS! ASS_CLOWN | |||
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Quote: OK, I can look at it that way. Then to optimize, one would use a high resolution instrument on the left side and on the right side, and tune the left side up close, but not touching the right side. So I work up a load with computer hooked up to my rifle. At 30 gr. IMR4895, 60 gr., .223, I measure that the primer pocket has grown microscopically larger. The computer says 84.5 kpsi. If we reduce that to 28.2 gr. and get 67.7 kpsi, fire 1000 rounds without any trouble in various conditions with the same bullets, brass, primers, rifles, OAL, and powder. OK, we found a good load, 200 fps faster than that load book's 26.6 gr., but 200 fps slower than the threshold of brass flow. So when we compare just working up until the brass gives, and then reducing 6 % powder charge to working up until the brass gives and reducing a pressure by 16.8 kpsi safety margin, how can we compare these two techniques? How can we measure how much safety margin we need?, in pressure? or in powder? I don't think we can. Is the only way to know, to shoot 1000 rounds again? | |||
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Quote: Hey Travis, Good analysis and I do agree with you. As to the above, I've given it a good bit of thought over the years and can point you in the right direction - they are FULL OF BEANS!!! Anytime I see someone quoting the "gospel" from a pitiful source of info, I eventually hear that old Carney Music crank up in my mind. But, they occasionally "Fool" me too - just not on this one though. HSGS = Reloaders Pyrite!!! | |||
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Hey AC, Looked a bit "High Stress" in that last post. Let me help you out and reduce your need for a cool one(or 6): HSGS = Reloaders Pyrite(aka Fool's Gold) | |||
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Clark... I think that's about right... and one good reason that I simply take SAAMI specs as a "given". There are two types of data in your reasoning, and if you're careful which of those you pick, the problem is at least reasonably solvable, if you're willing to put enough resources on it. Categorical (pass/fail) data are very weak. If you can put a number on something, then you can do a lot more... hence the distributions thing. It resolves down to a Stat Tolerancing problem... sorta like the RSS thing we talked about earlier. AC, there are now quite a lot of us now getting very repeatable strain gage results, that correspond very nicely with expected pressure values. Your estimate of being within 1,500 PSI is actually about what we are experiencing, or perhaps a little better. That's on a par with the repeatability of the methods used to generate published data, and actually pretty decent. Hot Core, you've told us all that you have a completely reliable, repeatable, calibrated system for measuring pressure, and that you do it with just a $20 micrometer. We keep waiting for you to tell us the PSI of some of your favorite loads, and to show us how your method works. If your claim is true, it should be no trouble at all. | |||
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Hot core, Good catch ! I was not thinking of pistols or shotguns either. This is absolutely for rifles of modern manufacture ONLY ! The first sign of excessive pressure in shotguns is shrapnel. And do not use this for 45acp, 45 Colt, or 45/70 vintage stuff either. Strictly a 50K plus PSI thing. PS: The " spider sense " thing was a joke, spoofing the idea that we can really actually measure pressure ( in PSI ) by the methods we have been talking about. Best we can do is judge by what we see and measure, and apply an educated guess as to whether it was : A...Not enough- too low a velocity, or sooty case necks. B...Enough - Worked as planned and did not hurt the brass, gun or primer. C...Too much - Caused damage to ( or failure of ) brass, gun or primer. The " hotrodders " always want the ragged edge between B and C , and sometimes find that C is alot closer than we thought... The guys who are assigning numbers ( in PSI ) to indirect measurements via SGS or brass measurements may be exactly correct. Or not. I dunno for sure. Travis F. | |||
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Hot Core, No not stressed, but enjoying your exchange with the others. Kinda like watching the kids fight over the TV, phone, etc. I don't think that the strain gage set-ups for sale today to the reloaders are any worse than PRE or CHE are, and may be marginally better (although there is the POTENTIAL for them to be far better). I don't use any of them much anymore. Not accurate enough, too much trouble, etc, etc. I use a chronograph, primarily. Have fun, I don't want to get too involved in the discussion, probably said too much already. Besides I have got a bunch of guys bustin' my chops over hang fires with reduced loads in the 300 Win mag using 4895 and 150 bullets. That is just too much fun. ASS_CLOWN | |||
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Quote: Hey AC, Good to hear you are not all Stressed Out. Neither am I. I get a bit of fun out of this stuff because I get to "expose" the TOTALLY BOGUS, completely unreliable HSGS fiascos for what they are. If anyone chooses to think their way through what I post (hopefully with a smile) then it is fairly easy to understand how denton is trying to FOOL them. I've never been able to understand his motivation for wanting to put such a device in the hands of folks that will eventually learn they have to "guess" at the Set-Up and then can't Calibrate it. Sure looks like a PT Barnum joke on the "Home" buyers to me. Lots of wasted money on - Reloaders Pyrite! As I've said numerous times, I do believe there is an excellent use for SGSs with firearms, but in order for them to work properly they must be Set-Up in a Lab which has access to a good CMM and also Certified so it can get Reference Ammo developed to SAAMI Standards and verified in multiple Labs. HSGS = Reloaders Pyrite! (aka Fool's Gold) | |||
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Now that this discussion has deteriorated into a hopeless urination competition... I have to say that any attempt to understand anything by anyone is a good thing for us all. The information we share here is a benefit to us all, whether we agree with it or not, it is more information than we had before. And maybe it made us think a little about conclusions that should really be thought of as ASSumptions. Read the last sentence of the above paragraph again. And don't blow your gun up. Travis F. | |||
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Quote: Hey Clark, Apparently "I'm" missing something in his posts. You have created a conflict in my mind simply because I "respect" your opinion. You must see something I don't. I have a difficult time believing a "rational" thinker can justify "guessing" at the barrel thickness and then claim a HSGS "accuracy" of 667psi(if that number is incorrect from his posts, it is unintentional on my part). When a person mentions accuracy at the hundredths, tenths and single digit level with any Strain Gauge, I know from my experience using them, it is just - Full-of-Beans. Then to "claim" anyone can Calibrate a HSGS using "Unknown Pressure Level" ammunition adds a second level of error to the overall HSGS. Tell you what I'd appreciate "you" doing for me. If you will explain to me how it is possible to get anything remotely close to useful information out of a HSGS where the person using it has to "guess" at the Set-Up and has no ability to Calibrate it, I'm all ears and ready to learn. Quote: The fine upstanding folks in KY who control such things are going to allow "Tyson" to box here when the folks out in Nevada told him they didn't even want him in the State. Maybe you are on to something. Quote: Excellent point! I've never claimed to be a strong WordSmith. But I can say: HSGS = Reloaders Pyrite(aka Fool's Gold) quite clearly! Is that what you consider "said better"??? Quote: Another excellent point. No argument from me(because I'm so amiable!!! ) | |||
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AC... Of course, that is a very good way to calibrate the bridge. The old system I had required that kind of tweaking... had to carry your little green screwdriver to the range. The new one is much easier. Its little uP reaches out every few seconds and balances the bridge for you, so you always have a fresh balance. That takes care of any thermal drift in the bridge. The amplifier in the system is an amazing little instrumentation amp, where the gain is determined completely by one external resistor. Put a little met film in that job, and you have incredibly stable gain. With all that, the need for the user to do any tweaking is gone. You only have a single channel, and you can't do some of the fancy stuff that you can with a real oscilloscope... like using two gages, etc., but that is a small price to pay for the portability and simplicity. No tweaking, no particular skill required. "MatchKing as a hunting bullet" was just a warm-up. Angels on the head of pin was kid stuff.  | |||
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Quote: So now you're saying that you can't use factory ammunition as a reference? What a pity. Ken Waters' PRE system relied entirely on comparison against factory ammo. You have just kicked the props out from under the system you are promoting. Of course, that poses no problem for a strain gage system, which is easily calibrated without factory ammo. Why don't you post the PSI of some of your favorite loads? You can't, because, as Ken Waters said, PRE is a relative system only, not a calibrated one. There are a whole lot of us out here, using strain gages, and getting very consistent results, that match very nicely with expected values. All the fact twisting and fabricated objections in the world can't change that. You can post all the reasons in the world that a plane can't fly, but once you see it in the air, you know those reasons have to be wrong. I thought I would never again see you tout your "experience" with strain gages, after you so badly humiliated yourself.... claiming to have 20 years of experience with them, and then being completely unable to answer a few basic questions about them. Hot Core has no facts, no figures, no physics, just an opinion based on an opinion he read somewhere. | |||
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HC, I am convinced that Denton is a smart guy putting allot of brain power into posts we get for free from him. And if our styles were less like Muhammad Ali [at a pre match weigh in] while addressing him, we might get more of that out of him. This is my theory on how others can see handloading pressure signs differently than us: 1) In handloading manuals, videos, and load data from the powder manufacturers, one will find the words, "never exceed max loads". 2) An order created through registered SAAMI max pressures, ballistic labs, load books, factory ammo, etc., that flows down this "never to exceed" information. 3) Max loads are developed by measuring pressure and that is reproducible measurement. We look like backyard cowboys, when we: 1) Categorize a gun as "stronger than the brass", overload it until something goes wrong, back off a safety margin, and declare our own "max load". 2) Say that, "All brass expands the same at the same safe pressure, whatever that is." Much better to them is: 1) The idea of a known pressure that already has the safety margin built in, and working up to that pressure seems safe. Changing the way we look at things is hard: I remember being 5 years old and not being able to figure out how an inner tube floated, if the water can't touch the air in the tube. It really puzzled me. So when I heard about density, I was ready to look at it that way. Those that are into measuring psi for individual handloads in strong guns are not so motivated, they have a working system that they believe in, and a whole support groups of load books. The onus is on us to sell our point of view. All we can say is, "Once you get really advanced, and are not afraid to overload, you get 200 fps more without buying psi equipment." That does not seem like a powerful incentive to change the way one looks at something, and I already look at it that way. Now, can you blame them? | |||
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AC, We are going all the way. We want to top, "How many angels can dance on the head of a pin?" | |||
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Quote: Yes. You plug in to the serial port. Don't know why they didn't use the USB port, where you could also get power for the interface, but they didn't. | |||
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