08-31-2020, 11:05 PM
Trashy, all of the water capacity measurements I see in the world wide web are all over the place. The 6 ARC measures 0.9207" from the top of the case head to the bottom of the shoulder while the 6.5 Grendel (and hence 243 LBC and 6 Grendel) measure 0.9507", so about 3.2% (or actually a little less since an equal amount of space is added for the area around the bullet in the shoulder).