30kg is total crap

[img]http://vignette1.wikia.nocookie.net/warhammer40k/images/d/dc/Heavy_Stubber_Vraks2.png/revision/latest?cb=20120203005610[/img]

This picture definitely says 7.8kg, which is much more reasonable.

I also found this while browsing the interwebs. Not saying that we should use it. But people come up with some actually cool and decent homebrew rules sometimes. 

https://www.reddit.com/r/40krpg/comments/1nh9d4/all_my_groups_fix_for_heavy_stubbers/