Author Topic: 44 pressure ?  (Read 610 times)

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Offline steelhead51

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44 pressure ?
« on: August 07, 2010, 04:59:52 AM »
The 44 mag is listed as being a 36,000 pressure gun but if you look at hodgen or other  reloading info the majority of loads excede the 36,000 lb. pressure so whats all this mean  if you load a 240 grain  bullet with 24gr. 2400 powder, you are past the limits or what , some things dont make sence to me in this reloading Hodgen manual shows a load 24.5 grain little gun under 240 grain jhp 38100  over limit, as with majority of other loads whats the realy story on the 44 mag and this data?

Offline MePlat

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Re: 44 pressure ?
« Reply #1 on: August 07, 2010, 09:24:24 AM »
This where reading and researching comes into play on loading data.
Hodgdons data is in C.U.P.   Copper units of pressure.
Sammi Specs calls for 36000 PSI (pounds per square inch) when using the piezo transducer system of measuring pressure or 40000 CUP when using the copper crusher method of testing.  These two figures are the maximum average.  There is a high individual max pressure in a shot string that pressure must not go over too.
Both systems use the very same calibration ammo to calibrate the two systems.
Hodgdons data IS NOT over spec you are wrong in your interchanging the two types of testing methods.
Hope this helps.  Researching things is part of the fun when dealing with ballistics.
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Offline wncchester

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Re: 44 pressure ?
« Reply #2 on: August 07, 2010, 02:59:14 PM »
"...whats the realy story on the 44 mag and this data?"

The guys who do the books know what they're doing and that includes the pressure system they're using.  Stick to book data, especially for handguns, and you'll be okay.  I think.  Occasionally anyway,  ??  I mean, it's scientific but reloading really an art, not a science so pay attention to pressure indicators no matter what the books say.  Most certain "pressure" indicator in large revlovers is sticky extraction, forget the signs that work for rifles or you'll blow your revolver from together.
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Offline Lloyd Smale

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Re: 44 pressure ?
« Reply #3 on: August 08, 2010, 01:51:41 AM »
when the 44 first came out it was loaded to higher pressures. Over 40000 was the norm. In this day of large liability lawsuits the pressures have been reduced. YOu could be seeing some of that as discrepencys in the loading manual. Many times when  a new manual is made alot of the old data is reused. 40000 psi loads are safe in any modern 44mag. using 250 grain or less bullets.
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Offline MePlat

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Re: 44 pressure ?
« Reply #4 on: August 08, 2010, 03:55:57 AM »
What the 44 Mag was loaded to when it first came out really wasn't the question.  I have never seen any pressure data on 44 Mag factory ammo from that time. It may have been higher than now,  it may have been pushed higher for a short period of time then brought back down.  I don't know and until I see some reliable proof that is was I don't really know.
Now people still use PSI when talking pressure data that was derived many years ago when Piezo tranducer pressure guns have only been in use for maybe 20-25 years roughly.  Not since the birth of the 44 Mag.
Even Elmer Keith use to quote his load specs from Whites labs as 34000 PSI when the Piezo transducer method of testing did not exist.   It was 34000 CUP.  
Now depending on the testing methos used today the MAP of the 44 Mag is 36000 PSI or 40000 CUP.
The pressure guns are calibrated with the same ammo.
Now on to the original question about Hodgdon load data.
It was derived on a copper crusher pressure gun and the data is in CUP not PSI so the pressure data is in line with SAAMI specs as to the maximum allowable pressure.
The OP confused the two as sometimes happens when one doesn't quite understand the CUP vs PSI thing.
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