Now from
Jan 1965 - Dec 1969 (It's amazing how a war will shorten the timeline. However current ones are done on a yearly basis until consolidated as this was in 1971.)
http://www.marines.mil/Portals/59/Pu...9000318100.pdf
1. No luck unless I missed it concerning the M202.
2. Look to 30 April - 27 May 1967 concerning the XM16E1 (M16A1) (The USAF actually ordered the M-16. The difference between the two was the "forward assist" which allowed for a manual "push" on the bolt group to clear jams.) during the Battle for Hill 881. I think this was the first major engagement the USMC used the XM16E1. I remember the controversy this caused and a little later for the USA.
3. Excerpts these from 1969...
A. Mar 3 USMC gets first CH-53D.
B. Apr 1 First four AH-16 Huey COBRA gunships start operating in Vietnam.
C. 14 Oct USMC---The UH-34D "Sea Horse" helicopter went out of active service after 12 years in Marine Corps aviation . The helicopters were transferred to units of the 4th Marine Aircraft Wing, Marine Corps Reserve, located throughout the country. (Flight Jacket, v . 26, no . 42, 17 Oct 1969, p . 1 .) This last copied over-who knows why?!? 
I'm getting the feeling that small arms aren't covered, at least in the older histories. Time to relax going in to rescue the "Sandman" in the morning at the end of the "O course".
Regards,
Pat