How much does a 38 caliber handgun weigh?

There is no one answer, because there is no one 38 caliber handgun.

First, assuming you are asking about a .38 Special revolver, and not a .38 S&W, or a .38 Super automatic- the weight will vary based on the size, and the material it is made from.

The current production Smith & Wesson 5 shot Airweight revolver with a 2 inch barrel weighs about 15 ounces empty. A 6 shot target revolver, with a 6 inch heavy barrel, made of stainless steel may weigh a couple of pounds.

No one gun, no one answer.