If they want the second amendment gone, why not repeal it?
First off, if the could, they would, but they can't yet and won't make a direct try until they think they will win.
Next, almost every session of Congress for many years now has had a bill to repeal the 2nd Amendment introduced. It never goes anywhere.
There is a specific process for repealing an amendment, and a bill in congress won't do it.
The process is to approve a new amendment which repeals a previous one, which was what was done to repeal Prohibition. Congress didn't pass a law repealing Prohibition. (doing that is beyond their authority) the NATION passed an amendment through the amendment process and that amendment repealed Prohibition.
there's a reason I'm using amendment so many times. The Constitution is the highest law of the land. Constitutional Amendments are changes to that law, and the process for ratifying an amendment is spelled out in specific detail in the Constitution. Laws passed by Congress are lesser or lower level laws than the Constitution, and since made by Congress they can be unmade by Congress, or the Supreme Court. The Constitution cannot be unmade or changed in any way by Congress or the Supreme Court, it can only be changed through the processes in the Constitution itself, the Amendment process or by a new Constitutional Convention.
The gun banners don't want an up or down vote on the 2nd A, its too risky for them. IF they lost that would effectively settle the matter for decades, possibly generations. They much prefer the current tactics of keeping the 2A in place but rendering it ineffective and essentially meaningless via regulations. They don't even really consider it infringement, or likely more accurately, they simply don't care as long as they can get what they want.