I don't have any experience with the AT One stock. I did put a Pro Varmint on a 6.5 and it fit perfectly. The finish was great. It did add some weight to the gun. I wish I had more info to give you.
I have two, one on a Remington and one on a Marlin.
Solidly built which means they are a little heavy.
Both actions dropped right in.
I would do a little bit of mod work if I was going to pack them around but these rifles are for youngsters set up in a blind.
I put one on my 25-06 and took it off a couple weeks later. They have a good idea going but basically they took a 2x4 and slapped an adjustable comb and butt pad on it. Stock is heavy, fit and finish suck, and the forend was no stiffer then the cheap Axis stock I was looking to replace. I've been trying to sell mine but on takers so far, if it doesn't sell I might do some sanding and shaping to see if I can make a stock out of the 2x4.