I've got a Ruger American in 6.5 Grendel (AR mags) that I would very much like to replace the mediocre-to-bad factory stock on, but, alas, the Magpul Hunter stock has no good magazine options for 6.5 Grendel. I am considering the MDT LSS-XL Gen2 "AR mag" version - does anyone have any experience with that version? My primary concerns are magazine compatibility and feeding reliability. I know it's new, but was hoping someone was running it by now.

I have their LSS or Mossberg MVP .223 that uses AR mags. Fit is perfect, so is function. You don't have to worry about MDT. They've got their shit together.

Very good. Forgot that they had already proved it out on that platform! I suppose I was just nervous because not a lot of chassis vendors are supporting the AR mag version of the RAR platform yet.

I have this setup in .300blk and it works.

MDT is good to go they have worked with me really well on my Oryx project. I bet it will work really well with your RAP.