(english) Tutorial Optimal Barrel Time with GRT

This video is a guest contribution from a friend, Cassie Nienaber from mamba-reloading.co.za
Cassie is a Member of our powder development team. He is a professional reloader and develops loads for clients. Since he has a very deep view and influence on the GRT development, his opinions and solutions can be very interesting and helpful for you. This video he made is a tutorial how to use the OBT feature in GRT.
He did a VERY great job creating this tutorial video i think. If you like his content, please subscribe to his channel. Please note that his company has no financial connection with the GRT project.
GRT Download: www.grtools.de/
GRT on Patreon: / gordonsreloading
GRT on Discord: / discord
regards, Gordon
original video and his channel: • OBT in GRT
Mamba Reloading: www.mamba-reloading.co.za

[@stanvizina6689]

Excellent video!! Thank you!!

[@Drakkarlegion]

Hoping to eventually use this for pre testing loads to start an ammo company. Amazing work guys!

[@observer4322]

Thank you so much for this!

[@csteenkamp]

Dankie Cassie!

[@TLtheofourie]

Wow great guys!!

[@firebladeflow]

Top, danke!

[@tommybreaux9430]

I enjoyed your presentation. Did you ever complete the instructional video that you mentioned at the close of this video?

[@stephan9561]

Hello, excellent Video! I have a question: why do you change at the end of the OBT calculation the Isentropic exponent (k) and the Combustion coefficient (Ba) instead of changing the calculated optimal powder mass (mc)?

[@ruanschmidt6207]

Hi, Stephan. My attempt to answer your question is out of pure ignorance here, but I think it has to do with the deviation factor of each powder lot. Each lot has a different deviation factor which runs unequal to the published data. I'm of the opinion that the powder data supplied on GRT is a rough guideline from many different testings from which this data has been collected over a period of time. As Cassie mentioned, we still have to change data on system according to our measurements, case cap, ect. That beign said, primer ignition consistancy also varies from lot to lot so I am of the opinion that we still have to adjust the isentropic exponent (k) and combustion coefficient (Ba) ourselves according to the velocity data captured from the chronograph. In other words, existing supply adapted to real world data. As with ES / SD, I'm not sure if this data would change once adjusted seating depth has been applied.

[@TheLightworkz]

Great video!!! I know this was specifically for rifles, but does is OBT also useful for pistols as well or just rifles?

[@andreroux1212]

Hi Cassie, het jy dalk n formule of excel sheet wat n mens die verskil in somchem se deviation bereken? Of is daar n manier om dit aan te pas op die program?

[@MrBbracken]

Is there a way to denote the use of hBn bullet coating? The result of using it is typically a slight reduction of friction in the barrel, simultaneously with a reduction of pressure behind the bullet

[@piwa1909]

hello, I have a question. Why do different results come out when calculating the BLT between Quickload and GRT? Is this due to the different powder data? It would be nice if someone would answer me!

[@piwa1909]

Hello, this is a very interesting video, even if I don't fully understand the second half. My mother tongue is German and my English is very poor. A translation into German would be very helpful. Gorden, that would be a great thing!

[@g.j.flyingjoss3076]

Why changing the initial pressure, and not the powder burn rate?

[@stepmasa248]

Das Programm ist Super. Aber dieses Video auf Deutsch wäre Toll. 🙂

[@piwa1909]

Bin der gleichen Meinung, die zweite Hälfte ist so etwas unverständlich, zumindest für mich!

[@MrBbracken]

There is one in German

[@lelandgaunt7130]

Thanks for the video. Would have been better without the music. Not everything has to be a hollywood production.