Show Hidden edges to reveal all 3 sided faces in a model

Collapse or convert your editable poly to editable mesh.

Make sure Show Edges is ON ... F4.

Then go to the Display Floater. Turn OFF edges only. We want to SEE the “hidden” edges, in other words, the edges that bound every 3 sided face.

Select ALL the edges [Edge rollout in your editable mesh]and go VISIBLE

Now our gun looks much more like a game object model. You can turn edges or make whatever edits you want to the faces.