Where can i find a proportionally accurate male muscular human 3d model?

I need one to use as base for modelling my armors.

You could download Makehuman and design your guy, then import it into blender.

Paul Chen’s free male basemesh for instance:

Comes in 3 different subdivision .OBJ files, and the original ZBrush file.
If he’s to skinny or too muscular, simply try “free male base mesh” - the web is full of generous people offering free, quality meshes.

Good resource. I can also use these as scale for pilot canopy of a small jet.