I did this with one of my slings, but found that the amsteel was slippery enough that my normal stopper knots don't want to hold unless I burned/melted the end to help it hold.
To prevent the adjustable end from pulling into the bury, I've also tried making a small locked-brummel loop. I'll look for "stopper beads" now, though I don't know what they look like!
How about that. 10 seconds on Google and I know what a "stopper bead" is!
Bookmarks