Gordon's reloading tool

[ACC]

I have been playing with Gordon's reloading tool. But it seems to me that I can input a load and it never even comes close to matching any of my reloading manuals. In fact I can input a load that is over MAX and it doesn't show that it is an over pressure load. Am I doing something wrong here? It's a great piece of software. Here is a screen capture of what I see. Any help here?

[fc60]

Greetings,

I, too, have been experimenting with Gordon's Loading Tool. There are so many parameters that can affect the end result.

If you go to the GRTools.de website, there is an opportunity to join the Discord forum. Here you can ask questions and get answers from the remaining team.

I compare my results with my friends QuickLoad data and we concur quite often.

Not perfect as yet, but a great piece of software for the price.

Cheers,

Dave

[megasupermagnum]

If it is anything like Quickloads, they can't accurately calculate anything except bottleneck high pressure cartridges. Such programs are kind of fun for comparing some changes, especially barrel length, but are ultimately worthless at predicting safe loads, especially in handgun rounds.

[jreidthompson1]

SAAMI MAX is 17000psi. CIP MAX is 21755.66. Which is what GRT is using.

Sent from my SM-N950U using Tapatalk

[jreidthompson1]

https://bobp.cip-bobp.org/uploads/tdcc/tab-iv/tabivcal-en-page57.pdf Note the max pressure listed in your GRT window is 1500 BAR converted to 21756PSI. If you change the max pressure in your window to 17000psi, GRT will warn you that you're over max pressure. I tried to match the other settings that you have input, but you should double check. 300374

CIP site
https://bobp.cip-bobp.org/en/tdcc_public?page=3&cartridge_type_id=4&cartridge_id=801

[justindad]

I’ve seen the same thing with True Blue powder in .45 Colt - at max book load it gives around 8ksi pressure. However, it matches book loads for .357 Mag with True Blue. This can be caused by the way GRT builds powder profiles - which only requires data from two different cartridges. This means that the way pressure affects burn rate cannot be accurately/completely captured or represented in GRT.
*
What I did with my .45 Colt loads is I considered the pressures as relative values (as opposed to absolute values) and did not go over 8ksi when changing to a different bullet or OACL. Worked for me, but I knew what I was risking. Also, my Uberti shows pressure signs as a particular screw will loosen before I get to 14ksi, which gives me a early & valuable warning sign. Tread lightly.
*
The best thing here is good on you for checking against a book load! Now if only different load books would all agree…

[popper]

I have found it works good for rifle and pistol. Beware, the seating depth it provides needs to be verified or changed to your value. I typically use Lee bullet data for my loads and vary seating depth.

[ACC]

Anyone know where I can find the most up to date SAMMI specs?

ACC

[mehavey]

https://saami.org/technical-information/ansi-saami-standards/

[mehavey]

"...ultimately worthless at predicting safe loads, especially in handgun rounds." Pick/load for data at mid-point of pressure regime.
Chronograph it.
Adjust "effective" burn rate to match that velocity & observe resultant pressure curve.
You now have a pretty fair/safe predictive tool for that family of bullet/powder as point of departure.

`Do it all the time w/ QuickLoad & any/all straightwall case cartridges

[ACC]

Any standards newer than 2015?

ACC

[mehavey]

What are you looking for ?
https://saami.org/technical-information/ansi-saami-standards/ are the current standards.
And except for brand new cartridges where new standards are just now set, I know of no changes of consequence.

[ACC]

Any body know how to convert CUP to psi?

ACC

[wyowillys46]

Any body know how to convert CUP to psi?

ACC

Here's some interesting reading on the topic.

https://www.shootingsoftware.com/ftp/psicuparticle2.pdf

[ACC]

That is some light reading!

I hate math!

ACC

[ACC]

Maybe someone can explain that to me.

ACC

[mehavey]

There is no conversion... apple & oranges.
SAAMI does have cartridge listings w/ both specs, though.
https://saami.org/technical-information/ansi-saami-standards/

As to the referenced article, just go to page-4 and look at the graph.
https://www.shootingsoftware.com/ftp/psicuparticle2.pdf
`nuff said,

[jreidthompson1]

This may be of interest also. CIP and SAAMI piezo and copper crusher values for numerous cartridges. A number of them are comparable.

http://kwk.us/pressures.html

Sent from my SM-G781V using Tapatalk

[ACC]

Has anyone checked this out?

https://calculator.academy/cup-to-psi-calculator/#f1p1|f2p0

ACC

[jreidthompson1]

It says 14000 cup =3322 psi so I don't think it's valid

Sent from my SM-G781V using Tapatalk

[megasupermagnum]

There is no conversion... apple & oranges.


There sure is.

CUP * 1.516 - 17,902 = PSI.

Example: 52,000 CUP * 1.516 = 78,832

78,832 - 17,902 = 60,930 PSI.

308 Winchester currently holds two SAAMI ratings. 52,000 CUP and 62,000 PSI, and it isn't an accident.

[mehavey]

https://i.postimg.cc/mZHR8tC6/CUP-v-PSI-Chart.jpg

Everyone on this Forum has direct access to the actual SAAMI standards of both CUP and PSI for individual cartridges.
USE THEM.... if you value your eyes and fingers.