Vietnam Era Veterans Exposure

I was in the Army from 71-74. In 72 I got a tatoo. During that
time the military used air compression guns for innoculations.
No IV drug use, happily married for 25 years.  Diagnosed HVC
positive in Jan 99 during routine annual blood test.  Have had
4 PCR quantitative tests, all of which came back negative.
(threshhold was 500pts/ml) Liver biopsy showed no permanent liver
damage, just a few enlarged cells. (I have been known to enjoy a beer or three).  ALT is 41. Spouse in negative.  Children are
negative.  2 questions:  1-Is it possible that at some time way
back then I was exposed to the virus but my immune system was
strong enough to suppress it?  2- Are veterans reporting high
incidence of postitive HVC? The "shot guns" were very unsanitary.
We stood in long lines (500-600) troops at a time and received
10-15 injections per day at the reception station.  If you moved even slightly at the time of compression, the guns cut you, and the next guy, the next guy, etc.  There was no indication of sterilization between use.  Am I a ticking bomb with the virus just waiting for the wrong time to attack.