Nope. An AR-15 weighs about seven llb; a loaded 100 rd magazine is five llb. Of course, you’d want more than one.
https://www.cheaperthandirt.com/kci-ar-15-magazine-.2235.56-nato-100-round-drum/FC-851586008016.html
Ok, still not 30 pounds but closer.
Of course I prefer a BAR so I really don't have any room to talk.
Grandpa sure brought some neat toys home.