Donald Trump is the ultimate flip-flipper. I believe that Donald Trump has no real value system of his own, and is just trying to get votes. He is against abortion because it's the Republican stance, and I believe his position on gun rights is more of the same. He knows nothing about actual policy, so he's just parroting Republican and Libertarian talking points.
Politicians will always say what they want people to hear not what is right, and Trump is no different. His recent sentiments that called on police to take away guns, despite claiming to a supporter of the Second Amendment is hypocritical and only aims at propelling him politically because he knows it will appeal to his right wing base.
Donald Trump has been pandering to the right wing base of his supporters throughout his entire campaign. Trump claims to be a 2nd Amendment supporter; however, he has also called for weapons bans. Trump is merely trying to appeal to both sides of the gun debate. He is not likely a big gun rights supporter.
No, Donald Trump is not trying to appeal to the right wing base because he already has them. Trump is trying to appeal to middle of the road Republicans that don't want to vote for him because of the things he has said and done. If he wanted to appeal to the right wing base, he would've said that what the police did was justified.