Regarding the Mossberg 590A1
2048 heatshield on a Benelli M4, it's not a common or recommended modification, and there's a reason for that. The Benelli M4 is designed to operate with specific features, including its barrel and heat management system. Attempting to fit a heat shield from a different firearm onto the Benelli M4 may not only result in performance issues but can also compromise safety.