Try this:
http://www.dtic.mil/whs/directives/c...df/133601p.pdf
It has been issued numerous times, but I believe with no changes from the original.
My service was similar, although prior to active duty, I spent 4 years in ROTC.
The 6month rule (180 days) is commonly called ACDUTRA... Active duty for training, and in essence is the dividing line between Veterans Benefits or not. (In my case, not, even though in actually counting days, the total was 182... no matter.)
After several reviews I was denied VA benefits,. It was an unusual situation. Normally, ROTC commissions require a minimum of 2 years active duty, but for a one month period in 1959, the government offered an "early out" (which still required a 10 year stint in Reserves). The reason was so many battlefield commissions after the Korean Was that the officer strength in the Army was almost 100% over the requirement. Since my bride was 7 months pregnant, and my "cut" orders were for Korea, I took the option. Today, this early out "for the convenience of the government" is almost unknown. Except for an obscure AR (Army Regulation) AR 135-173 SPN 501 ... no one seems to know much about this, including the Army lawyers JAG.
The acceptance or denial is sometimes a chancy thing... Some of my buddies who were similarly situated have received limited VA benefits... drugs and VA hospital...
The ACDUTRA classification (at least for officers) is the key. The pre 1980 rule doesn't apply.... though it sounds as if it should.
Filing is worth a try anyway... any extra days beyond the 180 should carry some weight even though in my case it didn't seem to matter.
The whole military service thing is rather strange... My only benefit after discharge as a Captain after ten years in the reserves, weekly meetings and yearly summer camp, is a $1 per month increase in my SS check. Not really complaining... the service was a good experience, though, considering that some of my classmates went up the ladder and in 20 years retired with a colonel's pay in 1979... I sometimes wonder what might have happened had I not opted out.
Good luck... your situation may be different... so don't give up yet.