(provided as a comment on H.R.2578 on the excellent website 4US.com)
H.R.2578 is a good example of legislative and political manipulation designed to confuse the public and hide important issue votes -- the practice of adding unrelated amendments, indirectly related and riders to bills under consideration. It is a ploy designed to deceive the public, sneak through legislation and make it difficult to hold legislators accountable. You can see here on the 4US.com website, the important significance of some of the amendments to this bill that were considered and voted on are not revealed and you cannot tell how your Members voted. Unrelated amendments are a significant contributor to Congressional gridlock and broken government and should be eliminated.
The primary purpose of this bill was to provide appropriations to the Department of Commerce, the Department of Justice (DOJ), science agencies, and several related agencies. Yet four, highly controversial amendments relating to gun regulations were offered and defeated in separate and very close votes.
See: Senate rejects all gun bills - Democrats and Republicans took turns defeating dueling proposals on background checks and efforts to prevent terrorists from buying firearms. June 20, 2016
See also: all details for H.R.2578 - Commerce, Justice, Science, and Related Agencies Appropriations Act, 2016, including amendments and links to roll call votes on the Congress.gov website.