Is the crosman 1377c made of high quality and durable materials besides the plastic forearm and grip?

Crosman guns are consistently made very well.

The 1377c is no exception to this.

As a point of fact, the 1377c's simplicity and reliability are part of the reason it has maintained in production since it was first released.

Also, as a note, if you plan on buying on of these, do a little looking for "custom 1377c's." There is a fairly large customizing community that has done some really cool things with their 1377c's!