Maybe it will go away, maybe not.
Remember that the Gun Control Act 68 was supported by gun makers, and representatives because a good part of it was a trade protection law.
It's provisions to restrict import guns (especially the cheap competition) were welcomed by US gun makers. And, American worker's facing job loss from cheap(er) foreign products was something politician's still took seriously back then. (they claim they do now, but the way things seem to work out, I have my doubts about how serious some of them really are...)
They supported it, then, because it was good for business. And Trump is all about business.
He'll bend some ways to do business with Russia, and bend other ways to keep the support of American businesses. Where he winds up on any specific matter is, I think, too soon to call.