The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading Re: 3030 Ackley Pressure Ring MeasurementsGo | New | Find | Notify | Tools | Reply | |
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Thought I would update the interested. The PRE is proving to be a very good and inexpensive way of telling where I am at with pressures. Key points for me have been coming up with a base load (factory ammo), a max load (.0010"-.0015" in modern bolt actions), paying attention to the chrony, making use of computer software (or others.... thanks ASSCLOWN), and having a consistant measuring technique with the mic. The 30Gibbs Elk load is the same as last year with a possible change in primers, 180XLCBT/61.5grH414/Rem280R-P brass/(either Fed210GMmatch or CCI250mag primer) for 2885fps(Fedprimer) or 2915fps(CCIprimer). I shot 1-5rd group with the Fedprimers to zero the sights this week and the group measured 1.5"high X 2"wide (slight breeze) @ 250yrds. Needless to say I am very happy with it. If I can get the CCI primers to group MOA I will go with them since the ignition will be more certain in cold weather. I am back on the 7-08 again (hopefully Wyoming Antelope and Colorado silhouette match in October, Colorado Deer in November). I shot 5 factory loads and discovered the PR's were identical to my 139SST hand load that I use for Deer/Antelope/Silhouette(out to 385m). With that being the case I will be loading them up hotter until I get into the .0010"-.0015" PRE range which I estimate will give me 2885fps+. Anyone have an idea of what my case life will be with a PRE between .0010"-.0015"? The 3030AI is still the last I will work with this year and I may not hunt big game with it this year since the Gibbs and 7-08 will be ready and will more than do the job. I might concentrate on a Coyote load using the Horn100SJ for 2900fps+. I would think that this would be a devastating Coyote load with its low SD and all of that exposed soft lead. Anybody have experience using this bullet and how it might do on fur (especially if it will pass through and what the offside exit will look like)????? Deke. | ||
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Quote:Hey Deke, It is extremely rare that anyone that has actually given PRE a "fair and unbiased try" would disagree with your finding. Quote:Yes indeed, "a consistant measuring technique with the mic.", is what PRE has ALWAYS done for well over 100 years. Quote:Hard to say because it will vary depending on how hard the Casehead is. This even varies from Lot-to-Lot from the same manufacturer. Quote:Never tried that one, but I agree that it should do quite a bit of damage on them. I have used the 120gr Speer Hot-Cor bullets on Coyotes and it does make fine Exits on them. Best of luck on the Hunts this year. --- HSGS = Reloaders Pyrite(aka Fool's Gold)  | |||
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Hey Deke, Real nice talking to you this afternoon. Sounds like you have a fine project in the works with the 30-30AI. As I think back, a good number of my Deer kills could have easily been made with that rifle. Be sure to keep the folks here informed about how well your Load Development goes. You just never know when one of them might want to have a 30-30 modified to become a "30-30AI" by Mr. Brockman too. Good luck with the "knee". "How `bout them TIGERS< !--color-->???" | |||
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Deke, please to not rely too much on the PRE method. I have tested it, and two pressures as far apart as 27,200 PSI can easily produce the same PRE. It's not that PRE is useless, it is just so unrepeatable that you can just barely distinguish a plinker load from a barrel buster. You have to average an excessive number of cartridges to be able to tell whether you are safe as can be, or saving up for a bolt implant in your forehead. This is not just opinion, or something I read in a book. It is based on a carefully done experiment. Ackley tested his loads with a copper crusher setup, and he reported safe 30-30AI loads of 34 grs 4198, 2700 fps;38 grs 3031, 2700 fps with 150 grain bullets. He also reported 39 grs 3031, 2940 fps; 35 grs 4198, 2940 fps with 125 grain bullets. Some feel that his loads can be too "hot"... you'll have to evaluate how much you want to rely on that data. I hope this helps. Good luck with your project. | |||
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Deke, Some data I just read off the Gunsmithing forum dealing with what URSAC used for receiver material in the M94 as late at the 1970's. Quote: There is a BIG difference in strength between SAE 4140 (what most bolt action receivers tend to be made of) and ductile iron! SAE4140 at Rc 25 has a yield strength of ~ 115,000 psi. Ductile iron will be in the 40,000 psi to 70,000 psi range depending upon which grade they are using (the ductility and impact strength drop off quickly between the 40ksi and 70 ksi grades too). This is the basis of the concern I spoke of in my last post. Now if Marlin uses similar material, and there is no reason for them not to with the pressure levels that cartridges are loaded to, I think you can see why I am concerned. As I stated earlier I think Mr. Ackley's recommendation is both wise and warranted. ASS_CLOWN | |||
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Ass_Clown Quote: Well stated.....but I'm very surprised at the use of ductile iron in a receiver.....can that be verified?? Quote: Again.....very true.....It was my impression that the Marlin was forged steel.....4140 | |||
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vapodog, The ductile iron comments were made by Savage99. I have asked him for additional information. I have a 1970 M94, and it had fired off some mighty hot loads. Scary to think it was a ductile iron receiver.  I am not going to chop it up though to find out (although the threaded holes in it look like STEEL to me and NOT ductile iron). I have little doubt that the original may well have been wrought or maleable iron. ASS_CLOWN | |||
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Deke, the "pressure-ring measuring BS is just that - BS!! Guys like waters should know better! For example the idea of firing a factory load then measuring the case is ridiculous, since many cartridges loaded to SAMMI standards are seriuosly underloaded for modern bolt-action rifles in good condition. This includes such numbers as the 7X57mm, the 8X57JS, the .280 Remington, and even the good ol' .30/'06! In addition, several labs have conducted tests in which it was discovered that rounds showing higher pressures with pressure testing equipment produced LESS case expansion than rounds that showed less pressure. This with EVERY VARIABLE being identical. cases, bullets, powder and primers from the same lot, same powder charge, etc. Basically, measuring "pressure rings", case heads, and what-have-you is no more reliable than looking at primers to see if they are becoming overly flattened! Neither works well enough to keep you safe! If you are working with a .30/30 AI, start with loads for the standard .30/30, and work up in half-grain increments. Your Marlin will tell you when you have arrived at the max. load threshhold for THAT INDIVIDUAL rifle! | ||
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Quote: Well...., let's see here. This seems to "claim" that one of the greatest Reloading Gurus of all time(apparently Mr. Ken Waters) dosen't know what he is talking about. Huuuuummm! Kind of sets the "believability" level for the rest of this post. Quote: Hey eldeguello, What exactly will the Marlin "tell you when you have arrived at the max. load threshold for THAT INDIVIDUAL rifle"? | |||
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Quote: Hey Deke, This is the part that is so humerous to me. Here denton is "criticizing" an excellent Pressure Detection Method which has been in use by hundreds of thousands of knowledgeable reloaders for well over 100 years. Obviously he just isn't able to comprehend the Physics and Mechanics that cause CHE/PRE to work so well. The thing that makes it EXTREMELY humerous is he "tested it" by using a HSGS which he had to "guess" at the Set-Up and he can't Calibrate! To "claim" the HSGS is accurate within even 50kpsi under those conditions is (let me say this kindly) Full-of-Beans.HSGS = Reloaders Pyrite< !--color--> (aka Fool's Gold< !--color-->) | |||
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Quote: Exactly so! Confirmed by my test as well. Hey Hot Core, on another thread, you claimed your PRE setup was perfectly repeatable, reliable and calibrated. So how many peak PSI does your favorite load produce? We're waiting. | |||
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Quote: Yup. In my '06, Federal Premium High Energy test at 58.9 KPSI, which is right at the limit. But the ever popular Super X runs only 51.9 KPSI. | |||
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Quote: Wrong on two counts. First, the test of repeatability which both PRE and CHE gloriously flunked does not use strain gage measurements at all. It just tests the method's ability to produce the same dimension, or dimension change, using only a micrometer. Hot Core knows this, and chooses to continue to ignore it. Second, the strain gage method is calibrated. It routinely produces results that correspond with factory figures. Calibration is easily accomplished, since pressure is a function of input variables that can all be obtained to three significant digits. It also easily passes the test for repeatability that PRE and CHE both failed. | |||
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Deke, I wish I had better news for you. The strain gage method works well if you can place the gage on the outside of the barrel, about halfway down the cartridge. Or, if you have a short cartridge, sometimes you have to put the gage at the mouth and use CIP (European) pressure standards instead of SAAMI (US). With a lever action, I don't think that is possible. PRE has difficulties that can be overcome, but which are probably insurmountable in your case. If you do shoot enough cartridges, you can "average down" the random error, and distinguish one load from another, but you have no basis for knowing which loads are OK and which are not. That's the problem you've identified, and I know of no solution. The best advice I have is to chronograph your loads, and to use a load that produces no more than 100 fps more than a conventional 30-30 load, using the same powder and bullet. It's not perfect, but I think it is the least "iffy" alternative. That sounds like a good, fun gun. Hope you enjoy it a lot. | |||
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To All, First thanks for the debate because it is benefitting me (and hopefully others) significantly. The reason for this post is I am developing a relatively low pressure cartridge and am at a bit of a loss as to determining excessive pressure. I have one other wildcat (30Gibbs) that is on a modern mauser bolt action. The 30Gibbs has proven easy to detect excessive pressure because it operates to a point which when pushed is very evident (primers, eratic velocity increases/decreases, then finally sticky extraction and head stamping at which point I definately back off). The modern mauser bolt action is capable of this kind of pressure, but I would think that the Marlin 1948 336 lever action is not. The PRE seems to be the most economical method of detecting the lower pressure limits. I see Denton's point of the different manufactured 3006 ammo producing very different pressures and that also points out the dilemna I am in regarding a starting point w/PRE since I am having a difficult time establishing that starting point with a wildcat that has NO factory ammo available. I am not opposed to other methods, but they have to be practical. I would be interested in learning more about the strain gage method, cost of equipment, and how it would be used with a wildcat such as the 3030AI. However, I would like to hear more about PRE and establishing a starting measurement without the benefit of factory ammo. Deke. | |||
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Denton, I am gonna speak my mind on this one. Loading a round that will unquestionably net 200-300fps more to only 100fps more is not what we are after. No disrespect meant, but I want to challenge us all to somthing better. I am not into wrecking a rifle (or worse....), but what you recomended kinda feels like pussycatting, not wildcatting...... I would be better off to come close to where I think I am at max without any pressure signs then test for case life (10+ without case failure), then load up another 1gr and repeat, and so on and so on. I would think that there is a better way. Deke. | |||
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I have no objection to you speaking your mind. In fact, I enjoy it. It may be that 100 fps is the wrong number. I remember some 30-30 loads being around 2200 fps. If you get 5% more case capacity by doing the AI, you have room for 5% more powder. The 30-30 is by no means overbore. So you can probably up your loads 5% from standard 30-30, and be fine. If that gives you 5% more MV, that would be a favorable outcome. You might try verifying the 5% estimate with a water test. It could be low. Ackley was positively derisive about the low pressure limits they put on lever action rifles, and backed it up with experiments. Maybe he was right. Maybe SAAMI was right. Maybe they were both wrong together. There is a lot of data that supports the notion that if you are getting "pressure signs", such short case life, you're up around 70,000 PSI. The bravest I've ever been is 65,000 PSI, in a strong bolt action. You might want to PM Clark. He's done a lot of testing of pressure limits. He might have a helpful answer for you. | |||
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