REF: 4" Model 617
You can have a lot of fun with a 4 or a 6 inch .22 revolver. Back in the early days of my police career, we carried 4 inch Model 19 revolvers, and the Model 18, which had a 4 inch barrel, was used by many Officers as a practice gun to always be ready for a perfect picture alignment with the sights. So, even if you are not a police officer, I would say try to look at both barrel lengths, and make YOUR decision. Don't let anyone else influence you. Remember that this is YOUR gun and YOU will be using it. Good luck, and I trust that you will make the right decision.