Gordon's Reloading Tool

Mr./Ms. Charlie...
Speaking down to users of GRT that are showing good faith in trying to help develop the program is not the best approach to be taking, if you want to grow the program.

Curt, dismissive, defensive emails are one thing.

Piling forum posts on top, that do the same thing, while talking down to your potential user base, is even worse.

There is a difference between feedback and criticism. Please figure it out.

There is also difference between idiots that can't figure out a calculator complaining about a computer program not spitting out the magic numbers they want; and knowledgeable, experienced, computer-savvy reloaders - many of whom have experience with other internal ballistics programs - trying to offer feedback on the UI, database errors, and massively incorrect calculations being spit out by the program. All you're doing is shooting yourself in the foot, when you automatically assume that EVERY person downloading GRT is an incompetent idiot.


...Which reminds me. I had forgotten about my first bit of feedback with the support ticket system.
When I downloaded my first copies of GRT on a laptop and a desktop, the inch/metric conversion wouldn't work on the laptop. It was stuck in metric and would not switch. I submitted a ticket. The tone of the response that I received was, essentially, "You're doing it wrong. Try it again. You're doing it wrong. Stop being dumb."
It turned out to be an issue with the installation being on Windows 8.1 and the bug was fixed a couple updates later. But, apparently, I was still .... 'doing it wrong, because I'm dumb'. :rolleyes:


I want GRT to continue development. I want it to succeed. I want to be able to use it.
But some attitudes in the GRT support community really need to change, before people will be happy to contribute. As of now, the people behind the 'support' curtain are discouraging feedback and data submissions.
 
Mr. Thoughts. You sounds like an American, but your posts come across as condescending as the email. As an user and supporter of the tool, I'm rather disappointed.

German language shouldn't be an excuse. I myself learned to speak a little bit of German by spending almost a year at Goethe Institute. I worked with coworkers from Germany, and I even stayed in Germany briefly for business. German people I have encountered, teachers, classmates, colleagues, train conductors, policemen, etc they don't sound like that.

Maybe you want to try again?

-TL

Sent from my SM-N960U using Tapatalk
 
Aguila Blanca said:
The bullet file was entered by the user, and marked as "Hollow Based", but the hollow base dimensions were not entered into the file.
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The hollow base dimension were not entered because there is no way in the new entry screen of the bullet database (that I could see) to enter it. If it's there, it's VERY well concealed. There is a place to toggle the bullet base, and this was set to "hollowbase."
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I have to correct my statement that there was no way to enter the hollow-base cavity information. There is a way. After reading the above posts from Charlie I went back and checked. And here's the problem:

GRT has a very nice interface. In this case, it's TOO nice. I have severe red-green color vision deficient vision. Red-green weakness is actually not unusual, but mine is at the severe end of a wide spectrum. The result is that many color combinations just don't "work" for those of us who are afflicted. People who design web sites should be aware of this, but my experience has been that they aren't. I have seen web sites or pages that were red type on a black background, which quite literally made the type invisible for me. If I knew there was type I might be able to drag the mouse to highlight it but, if I didn't know where the text was supposed to be, I couldn't do that.

How does this affect GRT? When you go to add a projectile in the bullet database, the form defaults to flat base and the entry fields for the hollow cavity aren't active. I won't attempt to assign a color to the text in those fields because whatever I call it will be wrong. If you click on the bullet base and change it to hollowbase, those other fields become active. Where it tripped me up is that the color change is so subtle that my defective color vision didn't see it. Once I knew to look for it I was able to detect it but, just looking at the page -- nope.

How prevalent is red-green weakness? Multiple sources say that it affects primarily males. Multiple sources also say it affects 8% of all males, but a higher predominance among white males of northern European ancestry. I've seen estimates as high as 15% for Caucasian white males.

So who is the most likely reloading community? Many countries don't allow reloading at all, so I'm going to hazard a guess that the biggest reloading community is American males, and that the predominant subset of that population is going to be white males of northern European ancestry. With that in mind, any graphical user interface needs to have the colors carefully selected to ensure that they work for people who either can't see colors or for people like me, who don't see colors correctly. Does it really make good sense to design a web page/site that 15% of your anticipated customer base won't be able to see [correctly, or maybe not at all]?

So ... having acknowledged that I did not enter the data for the hollow base bullet previously, I have now done so. And ... it made virtually no difference. GRT still reports velocity for the hollow-base Berry's bullet 250 fps faster than the velocity reported in the Shooting Times article. (931.7 fps for GRT, vs 687 fps for Shooting Times.) That's still an error of 36.6%.

I don't have samples of most of Berry's hollow base bullets. I have submitted a support request to them to request that data. Once I get it (if they can provide it) I'll update my copy of the bullet database and submit it to GRT. If Berry's can't give me the cavity dimensions, I'll submit a list of Berry's bullets without the hollow-base projectiles.
 
Color Blindness and GRT

For those that have any problems with the default GRT color scheme, our programmer has provided a method for changing the appearance. Please just look in the View menu. This option will bring up a screen where every element can be adjusted to user preference. Once the user has made his required adjustments, he can save it to a user named profile for transfer to later GRT versions, so the job will not have to be done again. The profile may require editing if the GUI has any new elements added, so the profile may not be completely forward compatible.

In this Appearance editor, there is a Preset field where the user can select either of two defaults. One of the defaults clones the QL color scheme, and that may be useful to some. I would post pictures, but this forum makes that difficult, or I do not understand the method.
 
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Comparing magazine published data to GRT Simulations

Quoting from a portion of your email to GRT. You state that you did not ask for any reply, but the general nature of the passage begs for a reply.

"For the 185-grain bullet, /Shooting Times/ reported velocities of 687
> fps, 762 fps, and 812 fps. GRT calculated 942 fps, 984 fps, and 1024 fps.
>
> I cannot understand this wide discrepancy. I did not adjust anything
> in the powder data -- I don't know enough about powder to try that. I
> hoped that GRT would be closer to accurate without my having to "tweak" the data."

With the passage being so general in detail, Gordon was only able to reply is a general manner.

I hope you can see that the data provided was sparce, in that it did not include vital elements like bullet length and construction, cartridge case measurements including case length and fired case volume. Without those elements, and a copy of your .grtload file, we have no ability to compare one to the other. Additionally, no actual user fired data corroborated the magazine information. I would be happy to process you questions if you can provide the proper information. You can send the required data to my GRT email address (charlie@grtools.de), or join the GRT Discord server where we can drop files and data directly when asking for help in figuring things out.
 
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Ewa Thoughts, your last post (#25) referred to using fired case volume for the 185 gr, .45 ACP example. QL advises using the sized volume for cartridges having less than 30,000 PSI max chamber pressure. Does GRT not agree? If not, why not?
 
Off the wall results.

I took the 185 gr, charge from Shooting Times (6.1 grs.) and using the measurements from some Win 45 ACP cases fired in my Para 45/14, I came up with a case length of .891", H2O volume of 27.8 Grs, and used an overall cartridge of 1.24". I then took your submitted Berry's 185 bullet (flat based dimensions) and placed it in my GRT simulation. I then adjusted the Initial Pressure (IP) using the Yellow Star wizard to Pistol and lead (as plated bullets act more like lead than hard ball). That made the IP 1160 psi. I set the Gas Seal at Soft Lead. I got a simulated velocity of 935 fps and peak pressure of 13584 psi. Subtracting the Shooting Times velocity from the GRT sim. velocity (935 - 812) = 123 fps difference, and dividing the difference by 812 shows a 15% difference.

I then looked at the picture of the bullet base on Shooting Times and measured the approximate hollow base dimensions. This was a guess, but I cam up with L = .3, A = .296, and B = .2". This is very rough, you may want to drop your actual measurements here.

Adding those hollow base measurements into the simulation produced a velocity of 838 fps, and a pressure of 10617 psi. So taking the Shooting Times velocity of 812 fps and subtracting that from the GRT sim. of 838 fps, I get a difference of 26 fps. Dividing (from your view point) 26/812, I get an difference of 3.2%.

Inspection of the effect of the hollow base dimensions on the simulation is not minimal, it is 935 - 835 = 100/835 = 11.9%. 11.9%/15% = .79, or 79% of the difference.

So now you may understand that the details can severely affect the outcome of the simulation. At least for this combination of components no warning of high or over pressure were displayed. You may also understand that comparing published data to any other published data is very difficult because the firearms and loading techniques vary so much. It much better to question results from your own fired results. I am sure that you have found differences in your fired loads as compared to published load manuals. That is at least comparing one party to another, not to a third party that can not speak for itself.
 
Higgite
The GRT simulation is not a copy of QL. GRT bases its calculations on the calculated final chamber volume as the case as expanded to fill the chamber. If the case did not expand, then the correct volume would be the case as sized. I will double check with Gordon on this however, to be sure I have not answered incorrectly.
 
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Ewa Thoughts said:
I hope you can see that the data provided was sparce, in that it did not include vital elements like bullet length and construction, cartridge case measurements including case length and fired case volume. Without those elements, and a copy of your .grtload file, we have no ability to compare one to the other. Additionally, no actual user fired data corroborated the magazine information. I would be happy to process you questions if you can provide the proper information. You can send the required data to my GRT email address (charlie@grtools.de), or join the GRT Discord server where we can drop files and data directly when asking for help in figuring things out.
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I didn't provide those data because I am not the author of the article. I sent Gordon a link to the article, and a copy of it. Obviously, I can't provide data that I don't have, but the fact that a published author in a respected mainstream publication had results that differ from GRT by as much as 37% speaks for itself.

As a writer and editor, I completely disagree that what I wrote "begs for a reply." It doesn't. What it begs for is a revised version of GRT that will generate results closer to what the real world experiences.

Since this exchange has gone from my intention of offering some feedback in the hope of improving GRT to a urination contest, I have gone back and tried playing with various aspects. Fixing the hollow-base bullet by inputting the dimensions of the cavity made a negligible difference. Just a few minutes ago I played with the initial pressure. Taking that all the way down to 500 psi (which is rather unrealistic) still left the velocities for the 185-grain bullet load about 100 to 150 fps faster than what the article reported as real world results.

This seems to suggest that the error is generated by something in the powder data, and that's way over my pay grade.

I have given you what I can. I obviously can't provide data that I don't have, and which I stated in my e-mail to Gordon that I don't have. Your continued harping on that appears more and more to be a defensive tactic rather than a sincere effort to foster a cooperative exchange.
 
Final

Since we are not able to communicate in a positive manner, I will discontinue any post here. I have tried to help, requesting a copy of your GRT .grtload file so I could vet the problem you are experiencing. However, all I get is I cannot give you any data.

Sorry I tried to help.
 
Sigh... I’m afraid we may have just tarred, feathered, and ran off an opportunity to have some constructive input with GRT. It is a FREE tool. FREE. And, more importantly, still developing and willing to take inputs from users to help refine data. I see potential for great value in that. I’ve personally observed it to be in the ballpark of velocity (can’t speak to pressure because I can’t measure it) on a few known loads, plus their results in most common situations seem to jive with loads listed in published data. The load that is way off is of the same sort that has already been identified to have similar large variances in Quickload, which is an excellent product but is not free and does not utilize user data to refine the model (to my knowledge).

I guess what I’m trying to say is “lighten up a little” and give them half a chance.
 
It is indeed free and pretty good. I appreciate it, and continue to use and support it. It could be even better without this episode though.

-TL

Sent from my SM-N960U using Tapatalk
 
One last thought:

Ewa Thoughts said:
I took the 185 gr, charge from Shooting Times (6.1 grs.) and using the measurements from some Win 45 ACP cases fired in my Para 45/14, I came up with a case length of .891", H2O volume of 27.8 Grs, and used an overall cartridge of 1.24". I then took your submitted Berry's 185 bullet (flat based dimensions) and placed it in my GRT simulation. I then adjusted the Initial Pressure (IP) using the Yellow Star wizard to Pistol and lead (as plated bullets act more like lead than hard ball). That made the IP 1160 psi. I set the Gas Seal at Soft Lead. I got a simulated velocity of 935 fps and peak pressure of 13584 psi. Subtracting the Shooting Times velocity from the GRT sim. velocity (935 - 812) = 123 fps difference, and dividing the difference by 812 shows a 15% difference.
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This is counter to what the GRT manual calls for. On page 32 of the manual, where the entry for gas seal/friction is discussed, it says:

GRT Manual said:
Solid Lead for projectiles which consist completely of soft lead. For such with polymer coating and/or thin, electrically applied copper layer or of hard lead choose "standard".
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Berry's bullets are electroplated. Consequently, when I entered Berry's bullets into the bullet database, I entered them as "Standard." Ewa Thoughts is correct -- when I changed that to "Solid lead" the error was reduced. But, according to the documentation, that's going off the reservation. There's no way a user could know that you need to go counter to the documentation to shift the results closer to real world results.

In fact, when you use the Yellow Star wizard, it sets the gas seal/friction entry to Standard for electroplated projectiles.
 
I’m afraid we may have just tarred, feathered, and ran off an opportunity to have some constructive input with GRT.
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There's a link to their Discord server on the GRT main page.
If you wish to have meaningful discussion, that's probably the best place to do it.
You can have live interaction - whether via text or voice chat - and get through a topic or concept quickly and clearly, rather than dealing with the slow nature of discussions and misunderstandings on a forum.


Quickload, which is an excellent product but is not free and does not utilize user data to refine the model (to my knowledge).
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QL sort of does, but you have to be part of the team, be able to measure chamber pressure (relative or actual), record velocity, and have a large enough assortment of test barrels to create good data for a powder, across a variety of cartridges. ...Is my understanding.

QL wants to be as accurate as possible, by modeling with a small set of the best data reasonably obtainable.
GRT seems to be okay with modeling based on a large sample size and a "close enough" average.
Both approaches have their pros and cons.


Right now, my issue with data submissions for GRT is the open invitation to submit real world data, but then there are a ton of hidden requirements, limitations, and exceptions.

For starters, there is the requirement for the data to be "2x2x2x5." That is:
2 cartridges (of different caliber)
2 bullet weights (per cartridge)
2 charge weights. (Min and Max)
5 rounds of each combination.

That works out to 20 rounds per cartridge, and 40 rounds total.

And, from discussions that I've seen in the discord server, they don't really want your data unless the charge weights are starting charge and max charge, and velocities were recorded with a Magnetospeed or Labradar.

So, you're basically just recreating published data, while dumping components into the dirt, and your data is "suspect" unless you shoot it over a Magnetospeed or Labradar.

They also don't want data from revolvers. Because GRT's model automatically reduces 20-40% of the velocity for firearms with "vents or cylinder gaps", depending upon cartridge and pressure, they don't want neutered (revolver) data to begin with. (This is from Gordon, himself.)

They also get picky about barrel length. For example, Gordon has stated that he doesn't want data for 700X, 800X, and "some other very fast propellants" unless testing was done in barrels at least 8" in length, with a preference for 14".

And, then there are the exceptions to the exceptions, that are, yet again, not listed or talked about anywhere.
For example: A user on their discord server asked if he could submit mid-range .300 AAC Blackout data from a bolt action rifle (since locked breech is what they want) to "fill in the gaps" and provide more data for the model.

The response was that his data would not be useful, since the GRT model for .300 AAC would be aimed at gas-operated firearms (understandably). And then Charlie unceremoniously directed him to create his own powder file for "nonstandard use" by using techniques in the GRT Optimal Barrel Time video: https://www.youtube.com/watch?v=XxDJVROdyxc


"We want your data!"

"Wait... That's not good enough, that's the wrong gun, you didn't fire enough rounds, your equipment was inferior. Oh, and this powder was on the secret list of special powders that have special test requirements that we never talked about or published anywhere. Also, again, your gun was wrong ... but the other, other wrong."
 
I tried matching QuickLOAD's 231 model to pressure and velocity data on Hodgdon's site for a jacketed bullet by changing the powder burn rate to change velocity and changing the start pressure (aka, initial pressure) to change peak pressure without much effect on velocity. Since QL allows start pressure to be changed continuously above 145 psi rather than just allowing fixed category numbers by the bullet construction, these two factors may be fine-tuned switched back and forth to get a match. I was at first surprised to find the start pressure had to go to over 8000 psi to get a match, but then remembered something I've posted repeatedly was at play:

In pistol cartridges with small powder spaces, it is not uncommon for the primer to unseat the bullet before the powder burn gets completely underway. I expect this was happening to Hodgdon during their tests. The amount of jump to the throat then effectively expands the powder space before the pressure has built much, and completing the initial burning stage (until the bullet is engraved) in that larger volume may well explain the big velocity difference. I still had some difference, but more like 30 fps over for the lower loads and slightly under for the top load. So I am thinking a jump in powder space probably explains a good portion of the velocity difference.

I made similar changes in GRT and got the velocities down, though not all the way. I do wish the start pressure could be varied directly in value and not just by the construction category (unless I am just missing the method of doing that).
 
For example, I always thought the term "Ja Ja' meant "Yes Yes", but in Berlin it means something like "Kiss my !@##".
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I did find this amusing. It's the usual problem literal translation of the words and what the speaker actually means.

And, just for what its worth, if an American tells you "yeah, yeah" or "yeah, right..." he usually means the same thing that Berliner does. (kiss my …..:D)

though that is not the literal translation of those words...

I found the discussion somewhat interesting, in general, but not anything important to me as I don't use any computer simulations, only real world results.

The discussion does prove that GIGO is still a valid thing, probably always will be. Garbage In, Garbage out. IF your data isn't exactlty what the program is built to "see" your results won't be, either.
 
Unclenick said:
I made similar changes in GRT and got the velocities down, though not all the way. I do wish the start pressure could be varied directly in value and not just by the construction category (unless I am just missing the method of doing that).
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Using the simplified interface, you can change the starting pressure to any value you wish just by typing it into that field on the screen where you enter all the load data. Ignore the gold star, and type in a value.
 
I've been following the discussions on GRT discord. Thought a minor update was in order.

Apparently, GRT just absolutely cannot compensate for anything outside of the pressure window the powder model was intended for.
This is one of several replies over the last week, in regards to people posting real world velocities that were more than 10% different than GRT's predictions, even with good data.

In this case, GRT predicted 2,101 fps, while recorded velocity averaged 1,803, for 7.5x55 Swiss GP90/03.

Response from Charlie:
Looks like the simulations over estimated the final results you experienced. That would be fairly normal as the pressures involved, and the fill ratio, places any propellant used into a completely different class than when the same propellant is used at, what today is normal, pressures (40000 to 60000 psi). For GP90/23 a special powder model would have to be developed to compensate for the burn speed differences. That does not mean you can not get good results, just high pressure models will not work for low pressure firearms.
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To be fair, QL predicted 2,082 fps. But, the powder used is unknown.
 
We have seen this in super light loads. It is quite alright for me. Software models always have limits. Good thing is the sim tends to be on the conservative side.

-TL

Sent from my SM-N960U using Tapatalk
 
Test fired another load of 7mm Mauser yesterday.

Bullet: Sierra #1950 170gr

Powder: 31.8gr IMR8208XBR

Load ratio: 65%<70%, a light load.

GRT sim muzzle velocity: 2235fps

Labradar muzzle velocity: 2163fps

# of shots: 9

So GRT is off by about 3%. Not bad at all.

-TL

PS. GRT indicates that the powder doesn't get 100% burnt. So there is unburnt powder coming out of muzzle.
 
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