A few of the other rounds listed something they called Max MG. I didn't see anything in the brochure explaining what that might be. I sent Eley a message asking what it means.
RSD = Radial Standard Deviation
MG = Mean Group
We use two methods to measure shots in our Proof Range depending on the product. Our premium brands for Target Shooting use RSD so we can really lock down the accuracy and grade the ammunition, Mean Group is used for grading ammunition used in the recreational category.