Muzzle Cap Installed:

First I inlet the cap onto the end of the stock. Then I drilled a hole thru the cap and the stock. Took a copper rivet, squared the head and then inlet the rivet into the stock.

Placed the barrel back into the stock and peened the rivet. (Note, I countersunk the hole in the cap for the rivet to fill the hole.)

Now I filed the rivet flush.

Now it appears the gun is taking shape.