My personal preference is the 6mm ARCin a mini Bolt action. Though for your intended use distance, & if factory ammo is a factor the 6.5 Grendel may edge out the 6mm arc. Pricing & availability of a variety of loads in 6mm ARC is simply, pushing the 6.5 Grendel to the better supported side.
As a bolt action die hard reloader guy, the 6mm ARC may arguably be better supported.
I was hog hunting in Texas last week. I used a Remington ADL in .243. It was serious overkill and excess penetration. I picked up a 7mm08 Ruger compact in December. Next year that will be my hog gun with 130 grain soft points down around 2500 or 2600 fps depending on accuracy. My longest shot was 50 yards. I didn't need a 90 grain bullet going 2900 fps for that.
kwg
Edit to add: I would take the Grendel.
kwg
