Thread: Gordon Reloading Tool

Hi all
I have just started to play with GRT and was wondering if there is any comment on the accuracy of the predictions? Seems like a very good guide with almost every possible powder and projectile in the database.
Thanks for your comments in advance.
Ruger7mm

It is an excellent tool, but like all tools responds best with good inputs, if you take the trouble to accurately measure case capacity and the other usual measurements, then chronograph a first few test rounds, it will be close. If you then use the OBT tool and calibrate actual velocity to predicted it becomes very accurate indeed. I was just using it tonight, went to the range this arvo and the second string of a load started showing pressure signs, then popped a primer. Back home, calibrated GRT and sure enough 68,000 psi - way too much and due to seating depth.

As above, really usefull especially when you recalibrate a burn rate or estimated V with validated speeds. Been using it for maybe 4 yrs.
Usually within 20 fps often much closer.

Thanks for the replies, it looks very detailed so will do some case volume measuring for the cases of the different calibres I am loading for, and get to more fun at the range. Thanks again.
Ruger7mm

@Ruger7mm havent read this post myself but it may hold some good info on using GRT

https://forum.accurateshooter.com/th...#post-38835206

Thanks John
Looks very helpful and informative. Will have a play tonight. I have done the water volume, projectile length, and other parameters that I can measure to help with load development and for GRT to estimate the pressure and velocity. I have loaded some combinations up for the 284 and will test at the range next week to see how they compare.
Cheers Ruger7mm

One thing to be aware of with GRT is "jamb" . I'm using it on some 223 loads I'm playing with just now, and with load with "a" it was within 15 fps of prediction, but I had some unexpected pressure signs on the load with projectile "b" as I hadn't taken into account that the different profile of the projectile was taking it up to the lands even though both loads were the same COL.