Now, let’s focus on the bottom of the casing. As you can see, we have a hole that we need to fill. That is the part where the trigger hits the bullet casing.

Create a cylinder with 16 segments in the center of the hole and chamfer the rim edges.

Add a MeshSmooth modifier with 2 iterations.

Next, we will add some marking at the bottom of the bullet caseing. Create the text object with a capital letter O.

Add an Extrude modifier on it and extrude it for a considerable amount.

Create two more text objects, another one with a capital letter O and one with a number 2. Also apply the Extrude modifier, with identical settings as before, onto them. Then arrange them to the positions like in the next picture.

Select all 3 text objects and the bullet casing and convert them to Editable Polys. Next, attach the 3 text objects into one editable poly. Select one of them, go to the Editable Poly options, click on the Attach button, then click on the other 2 text objects. Click on the Attach button again to exit the attach mode. Now we have a one text object that combines all three characters.

Select the casing and go to Create Panel -> select Compound Object from the drop down list -> click on the Boolean button. You will get a new set of options. Switch the Operation option to Cut -> Refine. Click on the Pick Operand B button and select the text object.

You should get something like this.

Next, apply the Editable Poly modifier to the casing (this is necessary because it changed it’s type from Editable Poly to Boolean). Turn on the Polygon selection mode and the newly cut in letters will be automatically selected. Extrude them inwards a little bit.

That’s it. Model is finished. Now all that’s left to do is add a metal material to the whole model or a material with clay like color like this: