Gordons Reloading Tool - A QuickLoad alternative

[williada]

Geoff, I will give you a bell. In short Geoff, you are merely fire-forming to produce a 7 SAUM with the gear you are using. GRT lists that and allows you to make changes to output by inputting your case volume, case length etc. There are other tweaks but too much to explain here. Quickload data can be imported into GRT too. There are few videos on You Tube where GRT is described in more detail. QuickDESIGN is the program for wildcatters which also takes into account internal barrel configuration for more accurate appreciation of pressure together with bullet design. It integrates with Quickload and Quicktarget. I would only use any of these programs to determine a safe starting load for load development based on approximate OBT. What's on the paper will determine what tune type suits the barrel or what tweaks in barrel lift need to be achieved or whether barrel length needs to be adjusted. I have been using the Pressure trace system with strain gauges since about 2000 which underpinned all of these programs but I have little call for it these days because the paper tells the story so long as the testing is safe and loads are worked up. Its just so important to run cases in as well as barrels and you get a pretty good understanding from that process with reduced loads what the barrel will do and where to start in serious load development when the cases and barrel are cherry ripe. Albert and yourself can confirm whether initial testing is a sound indicator the area in which the best load will lie. Its a matter of chasing the throat or a tuner to keep you in the right spot or if need be a total re-examination of seating depth to maintain correct barrel lift in the short run.
David.

[UL1700]

Well for what it's worth, I got home having been playing in the office, and with uncalibrated data its OBT was 0.7gn but only a few FPS off the speed for a load that showed significant promise (before Covid19) for my new Ftr barrel chambered for the 200gn Hybrids. It will be interesting to see what happens when I chuck the Labradar data in and finesse the case dimensions. for some range time soon!

It also thinks that even the most mild Ftr loads are going to kill you

[williada]

James you can play with bullet lead time values which affect the initiation pressure and maybe get some cross reference for initiation pressure from those who use QL to calibrate GTR if actual chamber pressures can not be measured. QL load allows you to play with burn rates. That's why I guess GTR is really a beta program at this stage and feedback given to the author is the way to improve it. There are a few tables on the web with regard to barrel length and expected harmonic frequency with a simple model. Accurate velocity measurement is essential, so any other fudges of programs have to generate the velocity you see in real life.

When pressures can not be established with a high degree of certainty, the fallback position for safely can be determined by knowing velocity and calculating energy from bullet data. I always look for pressure signs when working up a load by measuring the expansion of the rim, looking for flat primers or the ease of lift of the bolt handle. If there is nothing else to do, then these programs can keep you occupied for a long time. For highly experienced shooters, who don't want to wildcat, or fireform or compare calibers then their use of these modelling programs is limited. There are lots of ways to skin a cat.

[RDavies]

It also thinks that even the most mild Ftr loads are going to kill you

A few people send me their loads to run over my quickload and I have to agree. Many people are surprised at the pressures that quickload is saying they are running. Even accounting for the slightly reduced pressures with small rifle primer brass, some of the pressures people are running in F/TR are well into the red, some by quite a bit more than the person expected. It sure is a testament to the strength of out Barnard and other custom actions, but I wonder how many injuries would be received if people ran some of these loads in Omark actions?

[UL1700]

A few people send me their loads to run over my quickload and I have to agree. Many people are surprised at the pressures that quickload is saying they are running. Even accounting for the slightly reduced pressures with small rifle primer brass, some of the pressures people are running in F/TR are well into the red, some by quite a bit more than the person expected. It sure is a testament to the strength of out Barnard and other custom actions, but I wonder how many injuries would be received if people ran some of these loads in Omark actions?

I just chucked in the data for a mythical load I was told about on the mound and its nearly double the 60,000 psi spec for a 308 I'm starting to think that I may have upset someone

[pgcpty]

I've been using QL to good effect for some years now and recently with time available due to Covid-19 lock-downs have taken the time to get my head around GRT. My approach is to make side by side comparisons of the same cartridge data loaded into each and to compare results.
I chose 2 fairly commonly used 308WIN loads for ADI 2206H and 2208 powders. Note the high pressure/velocity load in 2208 is used only with Palma cases

GRT-QL COMPARISON of 308W 155.5 BGR TGT Tuned Node Loads for 2206H and 2208.jpg

The attached picture when opened in a picture editor has sufficient resolution to read all of the contents

I'm sufficiently impressed with the GRT results and features to gradually adopt GRT over QL for all future development work

My method was to inject QL data from my library and then run the GRT Optimum Barrel Time calculator including calculating the powder load to match with the node. Note, because there are full and 1/2 Nodes available flexing the powder load value can result in identifying the optimum velocity charge prior to adjusting seating depth by flexing COL in GRT to match the calculated Bt.
Observe on the GRT panels for 2206H and 2208 the Bullet Lead Time,10% pmax (BLT) of 1.2518ms and Optimal Barrel Time (OBT #3):1.2519ms is adjusted by flexing seating depth to get a close match.

I hope this input is of value to others and am interested in getting feedback that can be of assistance in getting the best out of this tool.

Peter

[macguru]

I have a mac pro and use parallels desktop for my virtual machines. .. I could use a PC as we have several of those here too but this works fine and I have 4 virtual machines .... windows xp, 7 and 10 plus macos 10.6 to run old mac power pc software. I have loaded GRT on the windows 10 vm and so far it looks very promising, provided you know what you are doing, and i gather from the other comments that there are a number of you in that category.

For instance, i'm blown away (excuse the pun) by the fact that it can calculate the optimal barrel time for my 31" saum barrel and tell me that my 57.5gr 2213sc load should be increased to 58.2gr giving me 2890fps instead of 2850fps !!! gosh I will have to test this now !! and see if its on the node .....

oh, wait... i'm locked down for the rest of the year because I live in Sydney - my bad...

[UL1700]

Many hours and hundreds of rounds stuffing around with the 308 and 200gn hybrids and when I went back to GRT we were within .1gn of each other (and I think the GRT load is better)!