The Expendables 4 brings the franchise back to its original R-rating, and there are some major reasons why it received the adult rating that parents might want to know about. When Sylvester Stallone created the Expendables franchise as a way to honor the iconic action movie stars from the 1980s, he did so by infusing the movies with high levels of violence and blood. This led to the Expendables movies being R-rated for the first two installments. The Expendables 3 made the controversial change to be a PG-13 blockbuster, but that mistake is not one that The Expendables 4 will repeat.

https://screenrant.com/why-expendables-4-rated-r-parents-guide/