Yep . As long as there good quality brass (shell casings) . You can punch out the old primer. Fit it with a new one. Reshape the neck, fill her with the amount of powder you needed for that particular load and press on a bullet.
It's only necessary If you do a lot of shooting. The equipment can be expensive and unnecessary for the individual who only shoots on occasion.
I compete in competition so I go through a lot of Rounds. I can buy powder, projectiles and primers in bulk saves me a lot of money. Another good side of it is you can load them how you want or need for certain situations.
Take for example. When I reload my 38 special, 9 millimeter, and 45 I use slightly less powder then would be in factory ammunition allowing for less recoil and faster target re engagement
It really all depends on what your trying to accomplish but for a competitor it's a must
