Gordon's Reloading Tool vs. Quickload?

[vonb]

I have found a new tool in the quest to better understand load development and refine handloads. It is called Gordons Reloading Tool and is similar to Quickload in that it can provide pressure information, OBT nodes and is free. I've spent the last couple days measuring case lengths and finding water volumes of fired cases to see what kind of pressure and OBT results would be the output. I'm excited by what this tool offers in hopes that I can reduce the number of round robin loads shot during load development and get closer to a node right out of the gate. Does anyone use both GRT and Quickload? Are results similar?

What I'd like to know from those that have used GRT are:

1) Are you finding the OBT nodes accurate provided you plug in the proper cartridge lengths, case length, water volume and powder temp?
2) Are you finding the velocity on par with your chrono readings given the proper inputs mentioned above?
3) What is the best way to "baseline" results with what your chrono is stating? Is it best to increase/decrease case volume so that it matches up with your chrono readings?


I've found some results to be spot on while others to be off a fair bit. If you haven't checked this out, it's worth looking into in my opinion. For now, I'll continue working up to loads until I have better confidence in this software.

You can download the tool here after registering. It will run on both Linux and Windows:
https://grtools.de

 

[Evan]

I have found a new tool in the quest to better understand load development and refine handloads. It is called Gordons Reloading Tool and is similar to Quickload in that it can provide pressure information, OBT nodes and is free. I've spent the last couple days measuring case lengths and finding water volumes of fired cases to see what kind of pressure and OBT results would be the output. I'm excited by what this tool offers in hopes that I can reduce the number of round robin loads shot during load development and get closer to a node right out of the gate. Does anyone use both GRT and Quickload? Are results similar?

What I'd like to know from those that have used GRT are:

1) Are you finding the OBT nodes accurate provided you plug in the proper cartridge lengths, case length, water volume and powder temp?
2) Are you finding the velocity on par with your chrono readings given the proper inputs mentioned above?
3) What is the best way to "baseline" results with what your chrono is stating? Is it best to increase/decrease case volume so that it matches up with your chrono readings?


I've found some results to be spot on while others to be off a fair bit. If you haven't checked this out, it's worth looking into in my opinion. For now, I'll continue working up to loads until I have better confidence in this software.

You can download the tool here after registering. It will run on both Linux and Windows:
https://grtools.de

I've never heard of this before. Thanks for pointing it out; I'll have to register and play with it some. Linux support is a big plus for me.

 

[rammac]

The biggest difference between the two is that the Gordons software uses three curves to simulate the burn curve for powders while QuickLoad uses only two curves. From what the reading I've done on internal ballistics, this may or may not be an improvement. Basically the theory is that the Gordon curve will fit the burn characteristics in the barrel better. I haven't worked a lot with Gordon's yet so I can't say how it compares with QuickLoad, mostly because I already own QuickLoad and I have very good luck with it.

Regardless of which software you use adjust the parameters that you don't know before the ones you know for sure. I always adjust burn rate values first and shot start pressures. Both of those can vary quite a bit because every lot of powder will have it's own unique characteristics, they are not exactly the same.

But if you change the burn rate by more than 5 or 10 percent then maybe you should adjust the shot start pressure. This parameter is reflective of the engraving forces required to push the bullet in to the lands. Needless to say, this pressure will change as your barrel wears or you change bullets.

I never adjust case volume simply because I can measure it and I know for a fact what it is.

 

[vonb]

Thank you for that. That helps me a lot. I was adjusting volume to fit the chrono speeds and it didn't feel right. Some of the models were within 6fps of what my chrono stated while others were 80fps difference. I really like the OBT analysis as the few I have ran, they appeared to match what I was seeing on paper/chrono.

It's definitely some interesting stuff if you take the time to figure it all out.

 

[SeabeeKen]

I’m finding the out calculations very close so far in my use of grt. I prefer grt over ql as it seems to be more versatile and accurate. I like that you can enter actual velocity and the program adjusts automatically and recommends a charge To hit the node.

 

[vonb]

I'm really enjoying it as well. The one thing I have not been able to address in GRT is when I'm using bullets with HBN coating. I'm changing the combustion coefficient to match velocities I'm seeing. However, that may be me having flawed thinking.

What is the right approach here?

 

[Scrumbag]

I quite like GRT...

 

[pgcpty]

I'm really enjoying it as well. The one thing I have not been able to address in GRT is when I'm using bullets with HBN coating. I'm changing the combustion coefficient to match velocities I'm seeing. However, that may be me having flawed thinking.

What is the right approach here?

Hi vonb,

Ive been using QL for a few years now, If you specify you're using a lubricant say hBN or moly, QL changes the Start Pressure, (Friction Proofed) to 66% of the default value i.e. from 3626 to 2393 psi. If you have your own data re naked bullet MV's verses hBN MV's, you could change this value accordingly.

I'm also playing with GRT and change the "Initial Pressure" to 2393psi for hBN.

Chs Peter

 

[vonb]

That's great information. Thank you for this.

 

[PopCharlie]

I recently downloaded and installed GRT. I have not used it though. Sounds like it need to dig into it.
PopCharlie

 

[VA_XTC_Shooter]

I get very mixed results with GRT. Sometimes everything lines up, more times than not, they dont. I am referrign to once I have real velocity data (magnetospeed) the nodes don't seem to work. Then again, I don't worry about a node, I don't think that model is 100% accurate.

I generally use to do initial pressure checks and estimates. Then do testing to fine tune a load.

One thing I did not like about GRT is it does not account for chamber dimensions beyond the neck. For example, short vs long freebore. It only focuses on the pressure inside the case.

 

[jelenko]

A guy named Cassie has done a few youtube videos on using GRT. In his latest, he mentions that, from his experience, about 40% of the predicted nodes don't work, but an adjoining one probably does.
From my own limited experience, I've found that about right. I.e., around 50% of the predicated nodes work after inputting the observed velocity and I've found powder/bullet, barrel combinations that work at some nodes and not others. It drove me crazy for a while. I assumed if one node was good, they'd all be good => spent more time than I should have testing at the bad node thinking it must be me.

 

[tsyarnall]

Great information!

Scott Y

 

[VA_XTC_Shooter]

A guy named Cassie has done a few youtube videos on using GRT. In his latest, he mentions that, from his experience, about 40% of the predicted nodes don't work, but an adjoining one probably does.
From my own limited experience, I've found that about right. I.e., around 50% of the predicated nodes work after inputting the observed velocity and I've found powder/bullet, barrel combinations that work at some nodes and not others. It drove me crazy for a while. I assumed if one node was good, they'd all be good => spent more time than I should have testing at the bad node thinking it must be me.

That to me indicates the OBT theory is not 100% solid. Just because you can get some to match, doesn't mean the theory is correct.

 

[vonb]

Inputs are just as important as outputs. If you're water volume, bullet length, OAL or any or other input if off, I have to believe that OBT nodes will be wrong. I've also seen in GRT where some powders have been researched more than others. Maybe this too could contribute to less than desirable results.

For me, I have seen OBT nodes dead on and then I've seen them way off. Some of the bullet lengths listed are vastly different that what I measure on the bench. I try to be as accurate as possible when I provide my inputs.

 

[jelenko]

That to me indicates the OBT theory is not 100% solid. Just because you can get some to match, doesn't mean the theory is correct.

Yeah. At the same time, overall, it has saved me time and components in developing loads.

 

[7Saum]

Hi has anyone have way different pressure reading from GRT vs QL?
I recently did a load up and it worked out to be very accurate on GRT, velocity, was almost bang on to my lab radar.
I told my buddy that has been using QL for years all my measurements and info and for that load it read 5000psi more then mine 76gr Reloder26 in a 300PRC with 212 ELD-X lapua brass, told me 62,800 roughly can remember exact number but with his calculations in QL it was over 67000psi.
The reason why I am asking is the Hornady reload data sheet says 76.3 gr of Reloder 26 runs 2900fps so I figured being under I should be safe..
Any help would be greatly appreciated..
Thanx

 

[jelenko]

Using just the values in GRT, I get 53,990 psi with a PRC 300 chamber, Hornady 212 ELDX, case volume 96 grains, cartridge length 3.7 inches at 70 degrees F and 76 gains of RE 26.

What case volume, bullet length, temperature and cartridge length did you use?

 

[Lone Hunter]

OBT using Gordon's Reloading Tool (GRT)

I've been using Gordon's Reloading Tool for the last 6 months. I'm amazed at the amount of data that the tool provides. I also really like the fact that the tool uses crowd sourcing to refine the data based on other's real data from a chrono, pressure trace, etc. With that said, for those that...

forum.accurateshooter.com

 

[Lkwebb]

Gordon's reloading has a discord channel aswell. I know mr. Gordon recently passed away but I think his coworkers are trying to keep it up to date.

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