The trunnion that held the barrel was minor more than a steel block dressed as desired and welded set up. The earliest barrels were being designed less than deal by Marlin and have been of Fantastic excellent. The Ingram Model 10 was made in the two 9mm and .45ACP variations. https://zanderzcwog.blogoscience.com/21787091/little-known-facts-about-mac-10-price