canoe on the yukon
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Ditto.....PSI and CUP are not the same thing however the SAMMI pressure standard was lowered.
?Excessively Hot 44Mag Load?
- Thread starter H Richard
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Ditto.....PSI and CUP are not the same thing however the SAMMI pressure standard was lowered.
Loomis Guard
Member
CUP (copper units of pressure) is just a tool to get the PSI readings!!!!!!! CUP is still used to double check Piezo transducer readings.. Jack O Coner or how ever you spell his name wrote an artical back in 63 about how inacurate all this testing equipment really is for any small weapons platform.. On any given day you might get any different readings on any test barrels for MANY REASONS!!!!!!!!! Now my personal feelings are that SAMMI lowered most of the pressures for the LAWYERS of this wonderful world of ours!!!! Not to mention all those Spaggetti Colt clones in .357mag coming across the pond!!! Oh well I'm off my rant now!!!
L.G.
L.G.
That is still incorrect. They are two totally seperate styles of measuring pressure, and have no correlation with each other. Back when "Jack" was writing, they didn't have near the sophistication in measuring devices they do now. One of the main reasons for switching to PSI from CUP was to be able to make much more accurate and repeatable readings.
The fact remains though, that todays pressures are lower than they used to be, and that goes for nearly all, if not all, of the magnum handgun rounds.
The fact remains though, that todays pressures are lower than they used to be, and that goes for nearly all, if not all, of the magnum handgun rounds.
Loomis Guard
Member
If you check the SAMMI website you'll see that they still use CUP for many catridges!!!! From my Speer #10 manual,,, PRESSURE--- The pressure exerted by a burning charge of powder in the chamber of a gun. Expressed normaly as the peak pressure in pounds per square inch (psi)----PRESSURE GUN--- Device for measuring chamber pressure in a gun. Usually of the "crusher" type or of the electronic "transducer"type!!!!! Now what bothers me MOST ABOUT the SAMMI site is their United Nation friendship...... We all know how GOOD the UN IS???????????
L.G.
L.G.
No one is saying that SAAMI stopped using CUP for some listings. They do. However, the .44 magnum's SAP (standard average pressure) has been changed from CUP to PSI, and it is a lower pressure than before. I know how they measure pressure using both methods, and there is no way to cross reference one to the other. The CUP method is known for not being nearly as reliable as the PSI method. A lot of ammo and bullet companies haven't been using the PSI method due to the extremely high costs of the PSI equipment. That is finally starting to change, and you will begin seeing more and more pressures given in PSI. You can call Hodgdon and querry them on a lot of this stuff BTW.
If you really want to learn about all of this, buy the A Square manual "Any Shot You Want". You'll learn far more from it, than any other manual out there bar none, as far as the technical side goes. It is the source for that type of info.
If you really want to learn about all of this, buy the A Square manual "Any Shot You Want". You'll learn far more from it, than any other manual out there bar none, as far as the technical side goes. It is the source for that type of info.
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OP
Well, I pulled all the bullets and re-swagged the case necks, and have reloaded 5 rounds with 18.0 Gr. #9. I also loaded 5 rounds with 13.0 Gr. HS6. (I later looked at one of my older manuals, Speer #10 and it shows up to 16.0 Gr. with the 240. Of course that is their 240, which has a different ogive and bearing surface. On the burning rate chart HS6 is pretty close to AA#9. I used to use 12 gr HS6 with a 225 gr cast bullet (25 years ago) and had good results. (In this same 44 mag barrel).
I plan t take these out to the range next week and see what they run and if there any "sticking" problems.
I plan t take these out to the range next week and see what they run and if there any "sticking" problems.
HS6 and AA9 same?
Richard, I don't know what your objective is and probably shouldn't interfere, but you've made some very contradictory statements that have me totally confused: "16.0 Gr. with the 240";"18.0 Gr. #9" And; their 240, which has a different ogive and bearing surface. On the burning rate chart HS6 is pretty close to AA#9." Are you short on bullets and in a rush to find the maximum load? Are you trying to destroy a perfectly operating pistol? Why the hell are you willing, or wanting to attempt to start with a maximum load when it would much more practical to start at or below an acceptable load and work upward to achieve a load that you and your pistol would appreciate and enjoy?
I may just be ignorant. If so, please, educate me!
EW
Richard, I don't know what your objective is and probably shouldn't interfere, but you've made some very contradictory statements that have me totally confused: "16.0 Gr. with the 240";"18.0 Gr. #9" And; their 240, which has a different ogive and bearing surface. On the burning rate chart HS6 is pretty close to AA#9." Are you short on bullets and in a rush to find the maximum load? Are you trying to destroy a perfectly operating pistol? Why the hell are you willing, or wanting to attempt to start with a maximum load when it would much more practical to start at or below an acceptable load and work upward to achieve a load that you and your pistol would appreciate and enjoy?
I may just be ignorant. If so, please, educate me!
EW
OP
Read my comment, I loaded 13.0 Gr of HS6. The Speer #10 manual listed 16.0 Gr. as max load, I am 3.0 Gr. below max which is 18.75% below max. My comment included that the Speer load would have been developed for their bullet and the ogive/bearing surface may be different than the Hornady bullet is a reason why it may give a slightly different load for this powder than a different bullet mfg. I have loaded lots of 44 mag with different bullets and HS6 over the years with very satisfactory results.
OP
It is only one of about 15 manuals I reference. I have some older than this and a lot up to current time.
DGNY
Member
44 Mag Load
H Richard - Good luck with your further testing. We look forward to reading your findings.
Regards,
Dyson
H Richard - Good luck with your further testing. We look forward to reading your findings.
Regards,
Dyson
Skip Sackett
US Veteran
This is from the SAAMI publication found here: http://www.saami.org/Publications/205.pdf
I haven't read any of the earlier publications but they state the intervals at which they have revisited these issues. They state that they are 5 year intervals; 1984, 1990 and 1993.
Now unless I can't do this new math right, that doesn't wash. 84 to 90 is close, only that's six years and 90 to 93 is only three as I figure it.
And these are the folks you follow for pressure regulations in firearms?
