I loved the M-79!
The only problem with it was the sharp edged corner on the base of the safety. If you didn’t get your thumb back over the wood on the stock after you moved it from safe to fire, it would cut your thumb tip after a few rounds.
Had to shoot up about 60 rounds on the West Range at Sill rather than take them through the tap dance of returning live rounds to the main ammo dump after hours.
Still have a little bit of the scar on the thumb from it. No real problem through.
Be well.