Seems like it shouldn't work but it does! - Daniel Defense EZ Carbine QD Swivel Attachment Point With Swivel 03-019-05026

If you back out the screw pretty far it should slip down any milspec buffer tube and hug the castle nut. Use some thread locker and give it good torque and it'll be a good one-point mounting spot that shouldn't move around.

NOTE: Depending on your stock and how many threads are showing on your buffertube you may have difficulty collapsing your stock to its shortest position. I use the B5 Streamlined stock (no storage) and it works fine, however the MFT could not collapse all the way. YMMV