I have had some modest success opposing gun control in private conversations by pointing out the ineffectiveness of proposed measures.
Banning assault weapons, however they are defined, addresses the use of a weapon that is used less often than bare hands for murder, according to FBI statistics.
Limits on magazine size only create momentary pauses in the rate of fire, which can hardly be expected to be a game changer in an active shooter situation. I have actually heard arguments that the magazine change will allow unarmed bystanders the opportunity to tackle a shooter. It is easy to demonstrate how foolhardy that is.
The effectiveness of our current background checks is compromised by two major factors. First, the database contains very little mental health information because our society currently values patient privacy more highly. Checking for mental illness using a database that does not contain mental health data, often by law, is a little past stupid. Second, officials in our government as high as the vice president have stated publicly that we do not prosecute straw purchases. Without fixing those two problems, increasing the number of background checks is just increasing the amount of paper generated, without any expectation of making us safer.
We are not opposed to making our communities safer - heck, that is why we arm ourselves. We have an opportunity to take the high ground precisely because we have thought about strategies of making our families, our homes, and our communities safer.