I just installed a Magpul PTS MSA (MOE Sling Adaptor) onto my Troy VTAC Alpha 13-inch rail, despite reports of the Magpul MSA not fitting on Troy TRX Alpha and VTAC Alpha elsewhere on the interwebs (post by IWC, proprietor of Mount-N-Slot, on AR15.com forums). Pictured below is the MSA mount mounted on the 9 o’clock position near the front of my VTAC Alpha rail (I’ve now mounted it at the 11 o’clock).
Simple enough. I don’t see what all the fuss was about with the MSA needing a flat mounting surface… it most definitely works fine on the Troy VTAC Alpha. That being said, it could just be IWC trying to make a sale of their own solution for mounting a fixed sling mount to handguard cooling holes, as IWC is a business after all. Not particularly impressed with their advice though: “It won’t. While the slots are the width and the thickness is similar, the MSA requires a flat surface to mount to. Atta hung it to the VTAC will touch only the center of the MSA, as the VTAC is round.” This doesn’t really make sense to me at all.