keep it in mind that anyone that conceal carry avoids things like vests, tight fitting cloths and anything that has a gun on it because it draws attention and it's hard to be "the gray man " with a tee shirt the screams "I love guns"... sorry guy
freedomdude, you're in your 20's, right? This site is populated by graybeards such as myself. We aren't the type that tries to call attention to ourselves. There's nothing wrong with your design or message, but it would play better at some site where the young hang out.
Personally I'd rather see people wearing pro gun shirts than anti gun shirts. If someone doesn't want to stand out that's fine of course, but IMO nothing is wrong with wearing a gun shirt as long as you behave yourself and don't make the rest of gun owners look bad.