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Mike,
I think you'll find that .30-06 pressure curve isn't too much like a pistol curve. It uses much slower powder that produces a much wider pressure curve. A pistol curve is much sharper in a normal 6" barrel or so. There's also the venting factor to consider in a revolver's barrel to cylinder gap that isn't present in a normal solid tube rifle. Most of what I've read suggests the powder is mostly burnt before the bullet leaves the cylinder, which is why a 2" barrel doesn't lose a whole lot of velocity compared to a 6" barrel. If you compare the velocities published in Speer #8 for a .38 Special 2" vs a 6" barrel, the powder producing the highest velocity in a 6" barrel was also the powder producing the highest velocity in a 2" barrel. |
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Paul,
Agreed on both points. I did not mean to say that numbers or shape of this chart apply to SR4756. Sorry if it came through this way. The chart was there only to demonstrate that different barrel lengths can change velocity without changing max pressure. BTW, I'd LOVE to see an actual pressure chart for SR4756 - that would answer a lot of questions we discuss here. Mike ______________________ 9x19, 9x29R, 9x33R, 10x22 |
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I've always assumed that the manufacturers know at least something about their powders. Published data show big pressure spreads for max loads. The max for powder X might be 10.0 at 38K, powder Y 8.0 at 35K. Why didn't they keep going to 8.2/.3/.4 with Y? My guess is that above a certain level Y gets finicky. Pressure SD's increase, and spikes occur. Just a guess.
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Interesting thought, pinky. Worth looking at other manufacturers' data from that angle. I noticed that Alliant has much tighter pressure spread than Hodgdon. All their loads (except target) for all bullets in 357 mag fall between 31,300 and 34,000 psi.
I think Paul asked a really good question yesterday. Charts and spreadsheets aside, proof is in the putting. If there is a problem with THE LOAD, how come Paul didn't get hurt after using it for 30 some years? 30 years amounts to a good solid testing period in my book... Off to make some loads and test them out. Can't wait to see what my soft WSPM primers will look like compared to H110 loads. Mike ______________________ 9x19, 9x29R, 9x33R, 10x22 |
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If the load is OK then why did Speer drop the load and why is it that IMR data is in conflict? Speer and IMR have pressure testing equipment they may know some thing you do not. “If there must be trouble, let it be in my day, that my child may have peace.” Fidelity-Honor-Valor 3rd Mar Div Vietnam |
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Omission isn't proof of anything. I'm quite sure there are historical events that aren't in the current encyclopedias, but that doesn't mean they didn't happen.
To think Speer is the same, whether it was owned by Speer Inc., Omark, Blount or ATK is absurd. Corporate decisions are made by the current owners without regard to the previous owners' decisions. That's pretty easy to see from when the Brits owned S&W or even when it was owned by Bangor Punta. The same concept applies to the current owners of IMR. Just because they choose to publish .357 Mag loads that develope less than 30,000 psi, doesn't mean anything above that is verboten. It also doesn't mean loads published prior to the current publication are unsafe. Of course, it should also be noted that DuPont published .38 Specials at 6.0 gr of SR 4756 with a 158 gr LSWC at 1000 fps with 15,800 cup in 1964, but in 2005, IMR was down to 5.4 gr at 880 fps and a supposed 16,000 cup. Are you going to try and tell me the "new" crushers are more accurate than the old crushers? 
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That doesn't seem credible to me...
In the early-mid 70s I was doing commercial re-loading as well as custom loading. I sold a lot of ammo to police and to police agencies... I don't recall any ever complaining about bullets being too effective... though some agencies only authorized .38 Spl, others allowed officers to carry anything they wanted and others had approved guns. We sold a lot of what today would probably called "killer" bullets because the modern JHP bullet had just hit the market and was not very available and we produced a knock off of those bullets that sold quite well indeed. I don't ever recall any issues with factory ammo damaging .38 spls. That is my recollection .... FWIW Chuck
Hoist On High the Bonnie Blue Flag That Bears the Single Star!!! |
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[quote]Paul5388;Omission isn't proof of anything. I'm quite sure there are historical events that aren't in the current encyclopedias, but that doesn't mean they didn't happen.
To think Speer is the same, whether it was owned by Speer Inc., Omark, Blount or ATK is absurd. Corporate decisions are made by the current owners without regard to the previous owners' decisions. That's pretty easy to see from when the Brits owned S&W or even when it was owned by Bangor Punta. The same concept applies to the current owners of IMR. Just because they choose to publish .357 Mag loads that develope less than 30,000 psi, doesn't mean anything above that is verboten. It also doesn't mean loads published prior to the current publication are unsafe. Of course, it should also be noted that DuPont published .38 Specials at 6.0 gr of SR 4756 with a 158 gr LSWC at 1000 fps with 15,800 cup in 1964, but in 2005, IMR was down to 5.4 gr at 880 fps and a supposed 16,000 cup. Are you going to try and tell me the "new" crushers are more accurate than the old crushers?[/quote You may rationalize all you want but the load is no longer supported by Speer and is in conflict with IMR data. You can only list pressure data from the Speer#8 current pressure data differs significantly. The Speer #8 seems to be your one and only source and from your point of view all other data is suspect that’s a reach. “If there must be trouble, let it be in my day, that my child may have peace.” Fidelity-Honor-Valor 3rd Mar Div Vietnam |
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Where did you get that from? Did you have "THE LOAD" pressure tested? Your summations are no better than ours, dennis. We all have stated that we feel that if it was a safe load then it should still be. You are saying that 30+ years, 100s of testamonies from folks that have used "THE LOAD", even police officers that loaded it and carried them, is of no consequence because it has been dropped from current manuals. To me that's a real reach. SKIP USMC 1973-1979 Born Again 1983-Eternity! .................................................................................... (John 17:17) KJV Sanctify them through thy truth: thy word is truth. "Some people spend an entire lifetime wondering if they made a difference in the world. The Marines don't have that problem" - Ronald Reagan   Unashamedly Christian, American, Male, all three of which are currently under attack! |
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Dennis,
I have Speer #8 and Handloader's Digest #6 that supports the loads I'm talking about. The only thing you have going for you is omission of the data after that. If you really had anything to support your cause, it would be something in writing that specifically mentions the issue at hand, i.e. a specific reference to Speer #8 and Handloader's Digest #6 data being unsafe. Instead, all you have to go on is statements like this from Speer #10. The use of "slightly" is pretty subjective and a whole lot depends on what the reader considers to be slightly, which could be vastly different from the intent of Speer (Omark Industries, Inc.). Speer #8 was published by Speer Inc., an entirely different entity. |
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I just found this from the U. of Michigan and thought it might be of interest.
It's 56 pages long, so I won't quote the whole thing.  I had to do some reformatting, so it isn't perfectly lined up, but it is sufficient for reading.Oh, BTW, the date on this is, "June, 1965" and the title is, "THE UNIVERSITY OF MICHIGAN INDUSTRY PROGRAM OF THE COLLEGE OF ENGINEERING ABSOLUTE CHAMBER PRESSURE IN CENTER-FIRE RIFLES" and "REPORT # 1 ABSOLUTE CHAMBER PRESSURE IN CENTER-FIRE RIFLES DU PONT BALLISTIC GRANT STUDIES" |
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Gentlemen,
Maybe it would help steer this discussion in a constructive vein if we agreed on what exactly statements like "THE LOAD is safe" or "there is a problem with THE LOAD" mean. We all know from Hodgdon that 7.8 gr. of SR4756 under 125 gr. XTP generates 31 kpsi. I concede it is almost certain that increasing powder to 12 or 14 gr. will increase pressure above 35 kpsi SAAMI limit. What does it mean? Does it mean THE LOAD can be used without care in any 357 mag gun as if it's backed up by gun and powder manufacturer? Obviously not. Any time anyone uses loads exceeding industry specs he is on his own and accepts all risks. We agreed on that long long time ago and had said that we recommend nothing and to no one. Does it mean that THE LOAD should be banned? If it is then any ammo exceeding SAAMI specs should be banned too including 9mm +P+ carried by countless police and military. Any +P and +P+ is “safe” in some guns but not in others. Several people in this forum reported that they tested THE LOAD in their guns and nothing bad happened. I shot it today in mine and it didn’t explode either. Paul was “testing” for 30 years! I doubt any manufacturer tests any ammo for this long. Yet, we shoot 9mm +P+ out of our Glocks and Sigs and noone looses sleep over the fact that it’s not listed in Speer #14 or any other manual. What’s the difference? So, when I say “THE LOAD IS SAFE” I mean that it’s okay for ME to shoot it in MY gun. I DO NOT MEAN that it’s safe for anyone else to shoot it out of any other gun. That’s all. Don’t know if this helps or not but sure hope it does. Mike ______________________ 9x19, 9x29R, 9x33R, 10x22 |
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I went back and added some emphasis on the report I posted. Just a couple of things I thought were germane to the discussion. I suppose I should have emphasized the errors inherent in using the Lamer Theory with strain gauges, but I didn't.
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Interesting, very interesting. SKIP USMC 1973-1979 Born Again 1983-Eternity! .................................................................................... (John 17:17) KJV Sanctify them through thy truth: thy word is truth. "Some people spend an entire lifetime wondering if they made a difference in the world. The Marines don't have that problem" - Ronald Reagan Unashamedly Christian, American, Male, all three of which are currently under attack! |
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Mike, (I almost called you rosey!) Here is an excerpt from the Speer #8. They had no doubt as to what these loads would be safe in. While the data may have disappeared these statements haven't been retracted, at least not to my knowledge. FOUND ON PAGE 367, SPEER #8 " Note that the loads recommended are the middle loads shown for the medium "K" frame gun. These heavy loads are safe in a Colt Smith and Wesson, or Charter Arms small frame gun, but constant use will result in loosening the action of the gun. All of these loads have considerable muzzle flash." Emphasis added by me. As I read that short statement it seems to me they weren't confused at all about what they were recommending as safe or what guns would be safe to shoot them out of. Obviously at one point Smith and Wesson thought that it's M640 was able to take much more than these rounds were developing. +P or +P+ hadn't even been thought of at the time this data was written. Still it is up to the individual to determine if their firearms are safe enough to shoot it out of. I too would have to mention what you have so eloquently stated, some have for over 30 years and haven't experienced any serious problems with doing so. I find it hard to believe that when the Speer #9 came out suddenly everything that had been said in it's previous manual was to be ignored. That for me would be a reach. SKIP USMC 1973-1979 Born Again 1983-Eternity! .................................................................................... (John 17:17) KJV Sanctify them through thy truth: thy word is truth. "Some people spend an entire lifetime wondering if they made a difference in the world. The Marines don't have that problem" - Ronald Reagan Unashamedly Christian, American, Male, all three of which are currently under attack! |
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