Remington, which is bankrupt, manufactured the Bushmaster AR-15 style rifle used by 20-year-old gunman Adam Lanza in one of the deadliest mass shootings in US history, which left 20 children and six adults dead.

The families of five children and four adults killed in the shooting launched legal proceedings against Remington in 2014, alleging that the company was partly responsible because of its marketing strategy.

Firearms manufacturers and dealers are typically protected from legal action after fatal shootings in the US under the provisions of the Protection of Lawful Commerce in Arms Act (PLCAA), which was introduced in 2005, but the marketing argument was novel, CNN reports.

Joshua Koskoff, the attorney representing the families, said: “The immunity protecting the gun industry is not bulletproof. We hope they realise they have skin in the game, instead of blaming literally everybody else.”

The settlement requires final approval by a bankruptcy court.