I just made 2 amsteel loop shackles (or nacrabiners or whatever you call them) and they only weigh 5 grams (about .1 oz) and my lightest 2 climbing carabiners weighed 2.1 ounces. That's a pretty good weight savings!
I already switched to whoopie slings on my main hammock, but I still like the convenient adjustability of straps for my backup hammock.
By the way, is there a knot equivalent to replace aluminum descending rings? (That would save another 4 ounces!).