it's cool that you're trying to be innovative. it's definitely unique, but like boby said you need to aim for either 125, 200, or 400.
I know that the piston shield is the main feature of this bot, but there's more weight efficient ways to pull off a concept like this. Most people trying to do a similar thing generally just use a row of weapons or plows in front of the piston ram to protect it (with enough space in the middle to allow the piston to extend and keep it DSL-S) which isn't as original, but it's more practical and efficient.
Keep building whatever you want, I'm glad you're being original. But also keep in mind alternatives, generally there's a way to save weight on whatever setup you build no matter what it is.