The first thing I need to remember, despite how other men view this, is that the woman has different views on security than we men do. Then I need to find out what she is comfortable with. Finally comes the decision of what to do. For us single men the choice is adjust to help her (not make her) feel more comfortable or to drop the relationship. For the married man, especially those who do not believe in divorce, i.e. Christians, etc., how to make things both comfortable for her but to also give us some freedom to enjoy the hobby we have chosen.
If we only listen to the extremists who always carry inside their house, those who don't aren't normal. But In all my life I have yet to visit a friend and see him carrying at home. It may have been nearby and loaded, but it was never visible to me. So to your girlfriend, it isn't what she is used to, normal or not. As to the videos, some is healthy, but apparently the amount you are watching is straining your relationship. She has a point that time on the range and hands on training will help you as much, if not more, than videos. At some point we need to put what we have watched into practice in order to be good at it.
Remember that it is only control if she starts doing things to get you to change, not just talking about it. Talking about it is healthy and is a normal and much needed part of a woman's life. The more you get it out in the open and talked out the safer and more comfortable she will be.
While you may see your "go for broke" ways as fun and healthy, she does have a point that moderation is a good thing. Since the newness wore off for me, my all out attitude and all consuming desire have faded some - to the point of a little each day with certain days/evenings set aside for the range, etc. I no longer feel the need to be immersed in guns 24/7 as I was when brand new. Yes, it is fun and new and exciting, but you have the rest of your life to enjoy both it and your girlfriend if you slow down a bit and remember to breathe.
How do I know these things? Women have taught me. Sometimes I learned the hard way, but lately I have learned more by slowing down and learning to understand that woman and what makes her tick. If we understand that they think,do, see, and communicate totally differently than we do, we have a place to start with making our relationship with them easier.
It might help, too, to tell her that you are doing this partly to protect her in case she is threatened. For those who think she's controlling you, this is reverse control. It will definitely help put her at ease.