Ian from Forgotten Weapons uploaded his 2nd part of the interview with Jim Sullivan. There are some factors well known now such as having no cleaning kit and non-chromelined barrels, but Sullivan talks about the significant change that probably had just as impact as the aforementioned two.
https://www.full30.com/video/d0b180478fa3b4bd8508e317f240f80e
From: Forgotten Weapons