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<.> |
Let's stir things up a bit: We all talk about "reduce the charge 10% when working up a new load." Well, load data in most manuals is already reduced 10% on the "maximum" end to begin with. I look at listed CUP/PSI and consider the gun for which I'm loading. My guns are new, in excellent mechanical condition, and well maintained. I'm not doing anything "experimental" on the load bench -- just the basic "bread/butter" reload. I never begin with a 10% reduction in a book published load. I reduce with online, "forum" data -- and check with published data too -- IF the load appears truly "maximum." But if it falls into the realm of broadly published data, I don't reduce -- not with standard components. I've never had "pressure signs." (And I check for them -- with a micrometer in some instances.) I'm loading some pretty "tame" stuff: 45 ACP, 38/357, 44 magnum pistol, .223 Rem. When I develop loads for .223 Ackley Improved, I reduce the "found" data and compare it to published .223 Rem. I run chronograph data on this stuff and keep copious records. Were I running some really "heavy" calibers, I'd likely sneak up on the max load. 300 Win Mag comes to mind . . . 460 Weatherby, 470 Nitro Express. But for run of the mill reloads, I just load by the book, at the "maximum" end of the chart. The indicated/published pressure data is no where near the maxium SAAMI spec. Corporate attorney's for powder/component mfgs. have reduced the load for you. But I'm certain there are those in here who disagree -- ------------------ | ||
one of us |
I think your methods are about the same as mine. I do compare sources even with book data. I also believe the pressure rating for any given round is conservative. BUT, when stuffing your own YOU decide what risk YOU will take. If you believe in what you know, performance can be streched quite a bit. | |||
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one of us |
I've da*** near locked up a bolt with "starting load" from one of the manuals. You guys have fun. I'll start at the start. JMO, Dutch. | |||
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one of us |
I may start with the listed max, but only if it makes sense, I know the guns strength from previous loading experience, and I have compared with other manuals. | |||
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one of us |
One of my friends shoots .300 Win Mag and .30-378 Wby Mag. He told me the .300 shows signs of pressure very easily, but the .30-378 doesn't show signs of pressure until the bolt gets sticky. So, unless you know how your gun reacts your first sign of excessive pressure might be a bolt handle that won't open. Also, I read in a book by Col. Whelen (something like small arms design) that the problem with MAX LOADS is if you accidentially load an extra grain and then take the gun out in the hot sun and shoot it, then you can get yourself into real trouble. I think I'll go with Dutch, start from the starting load. And, I think I'll stick with published max loads. I'll sacrafice 100 fps for a little extra safety. | |||
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<.> |
OK, let me add a few things here . . . I don't shoot in hot weather. We don't get hot weather around here. But were I shooting in hot weather that would be a different story. I've been loading for about twenty years. I understand pressure, seating depth, headspace, land engagement, etc. And I have some pretty specific data on my guns. Checking the older manuals, circa 1960's, I see that loads in current manuals have been significantly reduced. Elmer Keith's 44 mag load was "22 grs. of 2400." That's with a 240 gr. lead bullet. Today's manuals list a "MAX" load of 19.5 gr. (Hodgdon Data Manual #26, 1992) Lessee . . . 22 gr. minus 10% . . . That's 19.8 gr. Hmmmmmm . . . looks like the reduction is alread done for you. 19.5 gr. yields 36,000 CUP according to Hodgdon. SAAMI spec for 44 magnum is 40,000. Hmmmmmmmm . . . 40,000 minus 10% . . . that's 36,000 . . . Interesting . . . See what I'm saying? I see similar trends in other data -- lots of it. ------------------ | ||
one of us |
Have you considered that the current reloading manuals use current components? In the last 40 years the alloy of the bullet jackets, the powder burning rates, or the gas volume/solid ratio may have changed. It is also possible that there has been improved pressure measurement, different brass specification, or the adoption of more realistic pressure standards, too. Either one of those variables, or perhaps some other element I can't think of off the top of my head, are good enough reasons to use current data only. Simply assuming load data has been reduced to avoid liability may not be in your best interest. I don't mean to sound like a nag. Just my opinion. To qualify this, I haven't reloaded very long. [This message has been edited by Ben_Wazzu (edited 04-23-2002).] [This message has been edited by Ben_Wazzu (edited 04-23-2002).] | |||
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one of us |
A lot (read most, if not all) of the older data was obtained by seat of the pants guessing, by guys that blew up a lot of guns. Look at their methiods, increesing powder charges until somthing jamed or broke than back em off 1/2-1gr, guess the velocity and publish. None of the "greats" used pressure barrells and damn few had cronographs. Yes, the max loads seem lower today, but at least they have been properly tested in a controled enviroment with the proper equipment. | |||
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one of us |
I find your methods reckless, and doubly so because you have enough experience to know better. The simple fact is, powder formulations change, testing methods of manufacturers of powders, bullets, and primers change, cases capacities change, and simple typographical errors occur in reloading manuals all the time. A good example is a .270 I own. I started low and worked up, as is my habit. 60 grains of H4831 is the max load in my Hornady manual and I was using Hornady 130 grain Spire points. My rifle absolutely maxes out at 58 grains, with stiff bolt lift and flattened primers at 59 grains. Several posters on different boards told me they were getting 62-63 grains of the same powder in their cases and told of ridiculous velocities. Sorry, but if you change even one component, the only wise thing to do is to start over and work up. Anything else is just plain taking unnecessary risks. Just my 2.5 cent's worth- Sheister | |||
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<.> |
Never fails to amaze at the assumptions we make about statements of others. I don't use old data, and I don't rely on one set of data to formulate a load. I don't rely on "dated" SAAMI specs. YES, components change, powder changes, ballistics are affected. Nonetheless, there is a systematic trend in the data to reduce loads, again, and again, and again . . . It's not "new components" it's attorneys. SAAMI spec data affords a safety margin of about 5x between a functional load and a catastrophic failure. I find it ironic that Hodgdon provides "+P" load data for 45 ACP -- in one instance a 16% increase over the "maximum" listed load -- and in the same chart WARN that these +P loads "should not be reduced." Still . . . STILL . . . the published "+P" data is running about 10% below SAAMI spec for pressure. Plus P loads are NOT in excess of SAAMI spec for a particular caliber, they are merely loads which reach maximum SAAMI pressures specified. American ammo mfgs and reloading mfgs are running a very conservative operation. The industry is frought with liability on the face of it. The data is conservative, very conservative. Yeah, it's possible that you could load up a "max" round, shoot on a hot day in a specified gun and have some problems with bolt lift, etc. But that's completely different than approacing a catastrophic failure -- or even damaging the gun for that matter. AND, I'd suspect a gun that can't manage published load data (Sheister's .270) likely has a headspace issue that needs to be addressed. -- But that's a mechanical problem with the gun, not a safety issue with the load data. Please understand, I'm not "slamming" anyone in here. I'm being provocative in order to provoke some serious discussion about a serious issue. ------------------ | ||
one of us |
As far as I can see from your statements, you're as full of BS as you can get and not suffocate under the weight. I could go on about other's rifles and mine that have been at max at published max loads or below, but obviously you don't want to hear factual statements, only what you assume to be true. My .270 DOES NOT have a chamber problem as none of my rifles do, and yet most of them are at max pressures usually before book max loads. And this has nothing to do with shooting in hot weather- I'm experienced enough to make allowances for that regardless. 30 years of reloading everything from 38 specials to 375 H&H and just about everything in between have taught me a few things, and I still have all my fingers, toes, and eyes intact, thank you very much. You strike me as the kind of fool who advises everyone you know that the reloading manuals were all written by lawyers, so go ahead and just use them as a "rough guideline". Nothing could be further from the truth these days. The facilities manufacturers use to test loads is far beyond anything we can afford and their findings are pretty darned accurate. The only wild card in the mix is how YOUR rifle is put together. If you want to risk that on a lot of assumptions, just let me know if you use any ranges in my state so I can stay far, far away from you and your "assumptions".- Sheister | |||
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one of us |
I think it's hard to relay the emphasis for me when typing vs. actual conversation and for that reason I encourage you the reader to read carefully what is said. In my first post I said I compare data. All data. In the case of Sheisters .270 I would dare to say it will reach pressure signs early with most powders even using listed loads. When you load for a new gun you have no base info to start with, but when trying new, or different components ( with a known firearm) you do have background info to consider. When I was in my early teens I purchased a used '06 and when it was time to reload for deer I followed my fathers recipe. I loaded several boxes and used my rifle as the basis. Those shells wouldn't fire in my dads' Rem but functioned flawlessly in my Interarms. Differences do exist between rifles but if your gun has no peculiararities then comparing data to ensure it's within reason, and then loading some up within the printed data, I have never had a problem. I do start close to max printed data in all but one of my rifles and proceed past max "book" with much caution. I have a Rem 788 in .22-250 that doesn't like to funtion if the pressures start to come up. In that rifle load data maxes are pretty close but not over. I'll say it again. Each person has to decide for themselves how they will approach the max pressure issue. Many never go beyond listed loads. How then do they choose if max is lower in other books? Pick the lowest listed max? That is assuming they compare data! I have yet to see anyone I know blow up a gun, or injure themselves due to going to far. The max pressure listed by SAAMI is/does have a large safety margin. Maybe I just have very lucky friends but I'm not one who believe much in luck. I only have 23 years of reloading experience myself but believe that good sense will lead reloaders to choose proper loads and although there are idiots out there reloading I don't have any as friends. Here is advice to avoid... I do know a man, who once told me, he worked with a guy, who said his neighbor....( fill in wildest advice here). The one I was told was to fill an '06 case to the base of the neck with powder (4831 something) and pick any bullet. No I didn't follow his advice and he may even have meant well. Some people will be helpfull even without a clue. So in all this yes, reduce and start from scratch with an unknown, but with some history I don't think it's needed. | |||
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one of us |
Yeah, now that you have convinced yourself, what happens when another fast lot of RL22 hits? Where are those old and bold reloaders? JMO, Dutch. | |||
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<.> |
quote: I didn't inpugn your person nor your judgment. Why do you suppose it's OK to insult me? Address the issues. Leave the ad hominem for the rubes in Hillsboro. We can calculate bore capacity, load volume, bullet intertia, burn rate, barrel length, sectional density, and ambient temp to come up with stats. The books are full of fudge. ------------------ [This message has been edited by Genghis (edited 04-23-2002).] | ||
<ChuckD> |
HEY--people are going to think Oregonians have strong opinions! But Ghengis, I am damned glad we don't live too close to each other. I don't want to be shooting in close proximity to you--aversion to launcher shrapnel. You generalize to an extreme! In 20 years you seam to have acquired enough knowlege to become dangerous--but just sometimes, I'm sure. You stir things up about like Rosie O'Donnell would as an NRA convention keynote speaker!But , I'm sure you mean well (or need to be noticed). The thing is, this medium reaches too many people to allow this "information" to go unchallenged. Take care,---Chuck | ||
<eldeguello> |
There IS a potential problem inherent in automatically reducing a load by 10% to start with, IF ONE IS USING VERY SLOW POWDER IN A LARGE CASE WITH RELATIVELY SMALL BORE DIAMETER, and that is that there have been occasional serious pressure "excursions" with reduced loads of slow powders in some guns. There are, for example, powders that, in the MANUFACTURER'S loading data, a warning is posted "USE THIS LOAD EXACTLY AS SHOWN" and/or " DO NOT REDUCE THE POWDER CHARGE BELOW THAT SHOWN HERE", etc. So, we have to be careful not to use TOO MUCH powder, but, sometimes, we also must be careful not to use TOO LITTLE powder!! | ||
one of us |
Genghis, Hillsboro rubes? I remember now why I hate going into Portland any more than necessary. The assumption that living in a big city automatically raises your intelligence level would surprise execs at Intel and many others living out here in my neighborhood. You state you are trying to be provocative and you are surprised when someone is provoked? The simple fact is that your methods and message are dangerous. What happens when you are loading max loads with new components and you get an odd lot of bullets with harder-than-normal jacket material, or a new lot of powder that is hotter than normal, or some hotter primers, etc.... The fact is that starting at 10% below is the only way to assure that you won't find out the hard way that this is the case. Then you can work up to normal loads and proceed as normal. Your "calculations" and "fudge factor" can't account for all of that and guessing at any of it is foolhardy at best. On top of that, we all make mistakes, starting low is a simple safety factor that helps to eliminate some mistakes and work up and find problems before they become catastrophic. If you and your friends want to load in your manner, so be it, but don't print it on a public forum where new reloaders may not know enough to take your advice with a grain of salt. I use all the latest manuals, the best components and tools I can afford, and good strong actions and barrels, and I still find problems with many of the loads in the books. And that doesn't take into account the few times I have made simple mistakes like loading a bullet out a little too long, having a case that had a little tumbling media stuck in the far recesses of a cleaned case, etc... I just hope you don't shoot at Tri-County, there are enough guys out there who don't have a clue to safety. - Sheister | |||
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one of us |
I'm not advocating anything here and I don't want to get flamed for this but... What about consulting three or four different manuals, take the "lowest" maximum and reduce that by two or three grains and work up one grain at a time? It's not neccessarily 10% but I'd think you're pretty safe given some of the discrepancies of max loads in different manuals. Each test barrel was obviously different. | |||
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<Phil R> |
I suspect that those who recommend starting 10% below published maximum loads are in the business of selling bullets, brass and powder. I generally start 2 or 3 grains below the average max loads from several good manuals. I don't pay much attention to the Nosler Manual anymore as it was written by attorneys. I seriously doubt that any modern, properly maintained firearm has ever "come apart" from shooting maximun loads from the popular manuals. ------------------ | ||
<.> |
? [This message has been edited by Genghis (edited 04-24-2002).] | ||
<bigcountry> |
Well, I learned my lesson just recently on why to start 10% below. Using Re22, alliant says max is 90g with 180g Nosler PT in 300RUM. So I start out my usual 3 or 4 grains below max with Trophy Bearclaws. At 87g, I had stuck cartridges. So I tried the same thing with Re22 and Noslers, and went past 90g max up to 91g with no problems. Every bullet acts totally differet I found out. I can push Noslers past max, but not Bearclaws and Barnes. In fact Alliant recommends almost 10grains different in Re25 from Barnes to A-Frames. They recommend 81 or so for Barnes and 91.5 for A-Frames in 180g. So I learned 10% for safe shootin is well worth it. | ||
one of us |
Phil R wrote: "I don't pay much attention to the Nosler Manual anymore as it was written by attorneys." I have an older Nosler manual (#2) which list some pretty warm loads as max. For example the manual lists a load of 48 grains of IMR 4064 with the 150 grain bullets in 308 win. That load proved to be too hot for my rifle. I now use 46 gr. of 4064 with 150s. Some other manuals are more conservative with that powder/caliber combination. Don't know what the new Nosler manual lists for it. Have the powder companies changed the composition of the powders to any major degree since the early '80s? I guess I don't see the harm in being cautious with starting loads. Why risk injury or damage to your firearm? | |||
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one of us |
Several of these post repeat the same thing. When using load data for one bullet and switching to another you shouldn't expect everything to stay the same! That's why you tried something different! But if you have been using 180gr. Partitions in the same rifle, with the same brass, and powder, primer, and get a new box of bullets, do you reduce 10%? When you get a new lot of powder Do you always back off 10%? Or just a few grains? I think most people are not using the 10% rule as much as they preach! If you keep a load book of notes for each firearm and have references of past use, you should be pretty close even with new bullet / powder lots. I bet most people only back off about 3% and base that on past loads. If they have never loaded a particular recipe and they go dirrectly to max published data it's risky. Modern manufacturing is pretty consistant. Yeah I know about the hot RL22 but when getting a new lot of powder I do back off a little, but rarely 10% if I've been using the same recipe otherwise. It just sounds like the apples and oranges thing. Not really apples to apples. Why would you use max data for partitions when trying out a Trophy Bonded or whatever? Thats not working into a great load thats called stuffing shells. A lot to lot variation requireing a 10% reduction isn't something I have delt with. I didn't get any "hot" RL22 but from what I gathered in the bigger cases it's used in it still wasn't a 10% deviation. | |||
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One of Us |
Max and MAX +P loads are great for a few things, reduced barrel life, sore shoulders, comments like "wow that's a hot load". Sorry guys, but I've never found any max (hot) loads that were very accurate in any of my rifles, and I own more than a few. | |||
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<ChuckD> |
Well, Craigster You made one of my points--Why is getting to max loads right now, or any other time , necessary . I load my way up till I begin to loose accuracy, then work my way back to an accurate load. Parshal, pretty safe. Is that what Dale Earnheart was? I dont gamble with reloading. | ||
one of us |
I want to be on the more conservative side of the equation, since the penalty for the opposite can be so severe and irreversible. But I'm wondering how far to go with that. Here's my scenario: I am getting ready to work up a load for my brand new .375 H&H Mod 70 with 300 gr. Nosler Partitions. The most common "perfect" load that people (not just 1 or 2 people) have recommended is 72 grains of RL-15. Of course, I don't want to start there, so I go to the data manual and see what it says. The only book I have found (Nosler isn't available yet) with a RL-15 load is the Alliant book, which lists a charge of 66.5 grains for a 300 gr. Hornady. Now, if I take the book load and start down 10%, I am at 60 gr., working my way to 72! I'm not looking for a hot load, just an accurate, reliable load around 2450-2500fps. By the time I get to a decent load, I probably won't have a shoulder left! And as to the difference in pressure between Nosler and Hornady, I haven't a clue. My plan is to start out at 69 grains. OK, it's free-for-all time! Tell me what you think, what you would do in my place, where you think my head is, what my mother wears, etc... Rick. | |||
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<T/Jazz> |
I just got started in this reloading business for something to do and for knowledge sake. I am picking up things all the time from the elders of the gun club and the gun forums. I must say that I am in NO WAY going to start off at the MAX or near MAX of the loading data in any reloading book. I value my life to much, it opens the door for making assumptions that could mind you lead one down a very reckless and disasterous road in the near future. No two guns are alike when it comes to pressures etc. So I have been told by a couple of manufacturers anyway. There are to many different things that come into play regarding the realoading issue. Besides "One should NEVER get in a hurry" it isn't going to take that much longer and you aren't going to waste $10 worth of powder in the whole process. Sheister's approach I feel is the correct way to go about reloading. I don't approve of his less than gentleman like attitude mind you. However I feel there is no such thing as being to safe with a gun and the same applies to explosives and reloading shells or cartridges. I was told by a wise old man, to treat reloading like your Holy Bible......Don't Add To It.....Take It Word For Word! | ||
one of us |
An innocent question here in this sometimes heated topic: For those who start 10% below max. and work up for each combination of components, how do you go about doing this? By that I mean the specifics. Do folks load up multiple powder charges at home in 1 grain increments? And if so, how many rounds at each level do you load? Do you wind up pulling a lot of bullets? Or do you just make multiple trips to the range, working up each time? My range is 1 hour from home, so that option is pretty difficult for me to do. Does anyone load at the range? Only the benchrest guys seem to do this where I shoot. Do you use chronographed data in determining whether it's time to stop moving the powder charge up, or are you looking for pressure signs? Thanks. I'm always looking for others experiences to try to improve how I go about developing a load. | |||
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one of us |
[QUOTE]Originally posted by bjdoerr: [B]An innocent question here in this sometimes heated topic: I don't shoot benchrest but I load at the range with about the same set up as the BR shooters. When I get a load that groups about right I will chronograph that load. It cost alittle for all the stuff to load at the range but in the long run it has paid off for me. Well god luck | |||
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<eldeguello> |
dogtagger, the powder companies TRY to make their powders as close to the same performance characteristics as they can from one lot to another. They don't always succeed, and there have been cases of some significant differences from time to time, but these are rare. So, IMR 4350 today SHOULD perform reliably the same as it did in 1980. However, we must test new powder lots to see if this holds true, by working up to old load levels from some safe starting point from time to time. The one powder performance situation I remember the most was that Norma withdrew N205 from the marketplace in the 1970's because, for some reason that Norma never figured out, they made one lot of it that gave extremely high velocities with heavy bullets at normal pressures, and they were never again able to duplicate this performance!! Subsequent lots of N205 failed to give the fast speeds of this one lot! So, they brought out MRP, which performed pretty much like the "tame" lots of N205. | ||
one of us |
Rick3foxes. The Nosler 4th ed. had data for RL-15. Starting load is 64.0 gr for 2361 FPF. Max load is 68.0 gr. for 2490 FPS. FWIW. They show velocities to 2600 FPS with W-760. Next best powder is H-4895. Another FWIW. IMR powders are faster burning now due to a change in the material they use to make their nitrocellulose. I've had to cut a pet 30-06 load with IMR-4895 by two grains due to it's being much faster burning. Certain cartridges are DELIBERATELY underloaded by the factories due to the weak guns they were originally chambered. The 30-06 and 7x57 come immediately to mind. I see no reason why a careful handloader cannot exceed published max loads in these rounds when using a modern strong rifle. The buzzword is "careful". Proper use of a micrometer and chronograph can tell you when you've reached your rifle's maximum load, without blowing up the gun. When you buy a new lot of the same powder, you must start all over again. Guess that's why I buy my powder in the eight pound cans. Paul B. | |||
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<.> |
quote:
I arrange the loads in a case box with a tape strip across the inside of the lid specifying the load. I keep an OPEN row between the increments of loads. There are other approaches, but this one works for me, and I have lots of case boxes. 2) Half grain increments (0.5 gr.) between loads. I load 10-15 in each increment. This allows ample ammo for chronograph data and grouping. Just because the first round fires OK, that doesn't mean the load is necessarily OK. That's why we run a chronograph, standard deviation, and a micrometer on the brass. 3) A chronograph should provide you with an indication of "bore capacity." There's a point in the load increment when a half grain increase just doesn't give you the "standard" increment of increase in velocity. E.g. If you're getting 100 fps increase with each 0.5 gr. increment and then it drops to 60 fps, you're at the "bore capacity." You can load past bore capacity, but you'll spike pressure without much gain in velocity. Of course you MAY start seeing pressure signs before you reach bore capacity. ALWAYS look for pressure signs. The primer and the web seem to be the first place to indicate pressure problems. 4) I have a setup where I can load at the range. Depends what I'm doing. Sometimes I'm out on a "shooting expedition" and spending three/four days camped at a site. I'll load there if it's indicated. Mostly, I load the ammo at the home bench. It's more accuate, neater, safer, less bother. Yeah, we pull bullets. It's not hard if you have a decent bullet puller. I like the RCBS because it's rugged and warranted for life. I use a slotted spoon to catch the bullet from the puller while pouring powder back into the container. Make sure you're getting the right powder in the right container. (You knew that!) Too much data is always nice to have. I've discovered that ammassing data has reduced my ammo cost insofar as I spend more time figuring and less time shooting up the range. Each shot counts more. ------------------ | ||
one of us |
PaulB, Thankyou thankyou thankyou... I feel a little better knowing that someone besides Alliant recommends RL-15. I agree on the powder purchase, too. Once I'm convinced that RL-15 will tune in, I'll Otherwise, it would mean checking out the load every pound, which is only 100 rounds! Rick. | |||
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One of Us |
Ghengis, you dung disturber, you. Keep up the good work. | |||
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one of us |
I have faced Ghengis when he was on the opposite side of this at load your own and hard talk. I don't know if I am flexable enough to switch sides, so I will just quote from some flames my loads have provoked: You are an idiot However, this In the future, As you've Too, I've never If these simple --------------------------------
Posting garbage like this is Blow yourself up on your own --------------------------- If your goal is to blow up guns, thats easy to do. Overload them, place If you think that by experimenting with X grains of powder that will If you want a Magnum pistol, then get a magnum pistol. You won't be able
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one of us |
Gee, what a surprise! | |||
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<.> |
Clarification here: I think Clark's opinions about load data are probably accurate. I think Clark's methods in load testing are completely off the wall. There is a correlation between pressure and velocity. If you load according to data and record velocity, it's entirely possible to extrapolate some pressure data -- not directly, and not precisely. But you can extrapolate USEFUL pressure data regarding bore capacity and optimal load. In most instances, bore capacity is way beyond published "maximum" load data. But bore capacity needs to be measured with reliable tools. Physical/visual inspection of metalurgical integrity is hardly a reliable tool. And such inspections provide no quantitative data whatever relative to operating pressure. Most especially, repeated firing of an overloaded firearm will EVENTUALLY cause a catastrophic failure. PO Ackley tested firearms/loads by repeatedly shooting the same overload until it caused a catastrophic failure. That the gun holds together for one shot tells you practically nothing. That the gun comes apart after one shot tells you practically nothing. The "load window" we covet is not the point where the gun fails. The window is the point at which increased loads produce diminishing gains in velocity. This "window" is "bore capacity." The way to determine bore capacity is with a chronograph, some micrometers, and a careful statistical record of data. The "load objective" is not "to blow the gun apart." The "load objective" is NOT to blow the gun apart. ------------------ | ||
one of us |
I have been trying to map the slope of change in pressure vs change in powder charge for the pressure integrated over the time constant associated with the primer, case walls, and case head expansion. Then I try to map the slope of those pressures varying the OAL. This is different for each powder. But when I try bullet pinch, I get a steep slope of pressure vs interference. I go from normal to double the primer pocket diameter with a couple thousandths change of interference at the neck. When I try to measure powder vs chamber wall thickness at threshold of chamber wall spliting, that is where my current method is clumsy. I wrecked more guns today than I got at the last 2 gun shows I am going to slow down and take the advice of an old gun designer, "make inserts". I would like that chamber split data, but I think I should cut some 4140 inserts and wreck them. | |||
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<Sniper06> |
Current manuals are more afraid of lawsuits than they used to be before our sue-happy society came about. Just look at the Speer #11 Vs. the #12 on the .45-70 and many, many other loads. The #12 has the levergun loads at or below 28,000 CUP, and the single shots at or below 35,000 cup, and we all know the modern .45-70 levers will safely do 40K+, and the #11 listed the single shots at 50K CUP. And those were safe, I shot many top loads in my single shot before the #12 even came about. To a large extent, it is just companies practicing liability to cover their butts, and I can't blame them. [This message has been edited by Sniper06 (edited 04-26-2002).] | ||
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