Pressure - Reloading Manuals

Ammunition, reloading, shooting, etc
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Olpeddler
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Joined: Sat Nov 16, 2019 8:30 pm

Pressure - Reloading Manuals

Post by Olpeddler » Sat Dec 21, 2019 1:12 pm


Which, if any, reloading manuals include pressure data for all loads listed?  Thanks

Capt. Frank
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Re: Pressure - Reloading Manuals

Post by Capt. Frank » Sat Dec 21, 2019 3:34 pm

I have six, all only list min and max loads.

Olpeddler
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Re: Pressure - Reloading Manuals

Post by Olpeddler » Sat Dec 21, 2019 4:57 pm

Cap'n, thanks for confirming what I have been seeing.   I had a Lee manual published in the late 1990's and it did include CUP pressure data for each load it listed.  A couple of years ago I spilled a half bottle of Hoppe's #9 onto it and had to trashcan it.  I will call Lee's office on Monday to see if their current manual lists psi data.  Normally, I'm OK with only minimum and max. data, but now that I have a Model 1899 carbine, I am really sensitive to the 40,000 psi limit for .30-40 Krag loadings. At my age, I don't want to blow myself up.

waterman
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Re: Pressure - Reloading Manuals

Post by waterman » Tue Dec 24, 2019 5:16 am

Mike Petrov proved that you are not going to blow up your Krag, but it is pretty easy to crack the bolt at the lug.  That's why you need to  be careful.

madsenshooter
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Re: Pressure - Reloading Manuals

Post by madsenshooter » Tue Dec 24, 2019 7:00 pm

Sure miss Petrov, though I didn't know him personally. His posts have been a rich source of information on a Noske scope I have and a.22 Hornet Winchester falling block with Niedner barrel that a friend has.

KWK
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Re: Pressure - Reloading Manuals

Post by KWK » Tue Dec 31, 2019 8:17 pm

Lyman has the only modern pressure tested data I can find, for 3 jacketed bullet weights, 150, 180, and 220. That 220 bullet is out of production, but I don't know about the other 2 weights they tested (I haven't tried those weights). I have the 48th edition (2002), but the last time I looked at a Lyman in the stores it had the same data. Their cast bullet data has no pressure numbers.

Somewhat older data (1960s I'd guess, from DuPont) is available for IMR powders and two jacketed bullet weights. See the Hodgdon site; they still publish this data.

Lastly, the old NRA book Handloading (1981) has some pressure data from various sources.

Both the Lyman and the DuPont data are to the CUP standard for psi estimation. The NRA data is CUP, at least in part.

Sharpe's old book (1930s) has pressure numbers and some other equally old load books have such data, too. This is mostly for powders now long out of production, of course. These numbers are also crusher but predate the CUP standard, I believe.

There is no SAAMI standard for piezo psi sensors, so the only pressure data for it would be from handloaders using a PressureTrace or other strain gauge system.

Karl

madsenshooter
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Re: Pressure - Reloading Manuals

Post by madsenshooter » Thu Jan 02, 2020 4:44 pm

Different units makes things confusing! For example Olpeddler mentions the 40,000psi limit. No, not 40,000psi, 40,000cup. According to one of the powder company's ballistic techs I was talking to one day, 40,000cup would roughly equate to 47,000psi. In ADI's data for .303 British SAAMI MAX is 45000CUP/49000PSI It's only confusing I guess, if one fails to note the different units. That .303 data by the way gives CUP start charges with ADI powders for a variety of bullet weights that are below 40000CUP. ADI's Krag data however doesn't give start charge pressure. Capacity of the two cases is very close. Many Hodgdon powders are ADI powders.
http://www.adi-powders.com.au/rifle/303-british/
http://www.adi-powders.com.au/powder-equivalents/
http://www.adi-powders.com.au/rifle/30-40-krag

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Parashooter
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Location: NE Connecticut

Re: Pressure - Reloading Manuals

Post by Parashooter » Thu Jan 02, 2020 11:50 pm

. . .There is no SAAMI standard for piezo psi sensors, so the only pressure data for it would be from handloaders using a PressureTrace or other strain gauge system. . .

???
SAAMI has standardized piezo transducer method for years. They just haven't bothered establishing piezo pressures for some of the oldies, like our .30-40.

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Parashooter
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Location: NE Connecticut

Re: Pressure - Reloading Manuals

Post by Parashooter » Fri Jan 03, 2020 12:28 am

. . . According to one of the powder company's ballistic techs I was talking to one day, 40,000cup would roughly equate to 47,000psi. . .

Sounds right. CIP lists their piezo "Pmax" (maximum working pressure?) for 30-40 Krag as 3250 bar, which is 47137 psi.

KWK
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Re: Pressure - Reloading Manuals

Post by KWK » Sun Sep 13, 2020 10:07 pm

CIP lists their piezo "Pmax" (maximum working pressure?) for 30-40 Krag as 3250 bar, which is 47137 psi.
CIP piezo numbers are usually a bit higher than SAAMI's. Part has to do with how they define, statistically, the limit pressure. Part has to do with their using a different configuration of piezo system.

Do keep in mind the original Krag load of 220 at 2000 fps from a 30" barrel is maybe 35,000 psi, or a bit less. This is the level to which I load my rolling block, and out of caution, I wouldn't load an original Krag any higher. IMR 4895 works nicely for this.

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