Two of those companies tripled such revenues over the past three years, a House investigation reveals

Those profits have come as the weapons were used in mass shootings that horrified the nation, including one that saw 19 children killed in Texas

US gun manufacturers have made more than US$1 billion from selling AR-15-style guns over the past decade, and for two companies those revenues have tripled over the past three years, according to a House investigation unveiled on Wednesday.