It's time for a new barrel. I was looking for the perfect 6mm chamber ( light recoil and long barrel ) for my Savage when i came to the conclusion that the 6mm grendel was the right size, so why not modify the AR. Before you ask why 6mm, not 6.5 grendel, let me explain. Most grendels shoot something like a 123 gr with a g7b.c. ~.26. People say anything with a higher b.c. takes away from case capacity. A 6mm in the 105 range is going to have a higher b.c. and the Berger 95vld is short enough to avoid the doughnut, while being light enough, the extra velocity should make up for the reduced b.c. at 600 yards. Well if a 105 going 2700 is to going be better than the 6.5 123 at 2600fps, maybe a Berger .224 90vld with a similar b.c. going faster will be even better. Same length as the other bullets. Questions: 1. Has anyone used these calibers? 2. What velocities can be expected? 3. And can I give a gunsmith a dummy round at mag length to make a throat that will allow the bullet to seat at the lands, with the hope that near max length is right at the lands?