I was super excited about the 30 remington ar when I first heard about its creation. Then I went looking for one locally?? At that time I was ready to pay the price for one in the r15. I was not able to find one anywhere near where I live. I believe this cartridge was brought out right when the prices went up on all ar type rifles. I think the prices got so crazy and the availability of rifles, ammo, no cases for hand loading all these factors killed this one before it got going. If it sticks around it might find a following. It will fade if they don't start making cases for reloading.
