I'm new to the AR platform and looking to get the 6.5 grendel for a varmit hunting rifle. I'm used to a bolt action rifle where barrel length is key to long range shooting. So I have been looking at the 6.5 grendel in a 28" bull barrel. I will be reloading my own loads and am not worried about standard factory ammo burnning too fast. However, after talking to some gunsmiths they are concerned about such a long barrel on the AR platform with a free floating barrel. I have been told that the barrel nut will not hold such a long barrel and could get too much wip. Any suggestions, should I be looking at a 20" barrel instead?