How should I fix this topology issue? I'm a beginner modeller, and I've been trying to create a revolver from a reference photo. I've been tweaking the topology here and there to make sure that I have no 3 or 5 vertex faces. However, when looking at the model with a subdivision surface modifier I get this weird pinched effect that you can see below

What am I doing wrong and how can I fix this? All answers are appreciated!
If you are a begginer you should try less complex objects before try to create a revolver.
Look at YouTube for tutorials about booleans, crease, edge split, bevel and other hard surface tools.
To solve the problem you post try to use bevel modifier or add more loops (ctrl+R) near that junction.