When I wasn't pulling a shift in FDC, I'd hang out by the guns to see if they'd let an amateur pull the lanyard. Sergeant Don was agreeable as long as they were setting defensive targets. He even taught me how to dial in the elevation and deflection. It may sound dumb, but when you're on a firebase out in the middle of nowhere, there wasn't much else to do in your spare time.
I never intended to write about the experiences of my tour of duty, but my mind changed over the years. I had an unusual collection of stories that I figured many would find interesting and I wrote my memoir a couple years ago. It's gotten pretty good reviews and sold over 500 copies. 363 DAYS IN VIETNAM is available in paperback and ebook on Amazon:
https://www.amazon.com/dp/1645709191
That's me (left) and Don (right) and his 105MM.