Four guns. Each gun comes with 2 barrels.
16,000 rounds of ammo.
Do the math.
4,000 rounds per machine gun.
To maintain a steady shoot, you are supposed to swap out barrels every 200 rounds. Each time you change the barrel, you MUST check the head space. That's 20 barrel changes per gun.
That was a good day of training. We got premission to actually fire the guns from the tops of our "Tracks". Normally that range would only allow you to fire the guns from the tri-pods. However, I had come up with a safety plan that was approved by the head range dude.
Let me tell you...there is nothing like shooting a Browning M2 HB 50 Cal Machine Gun.
We ended the range at 2300 hours (11 PM for you civilians). We had expended all rounds. However, we kind of wasted 7 out of 8 barrels.
That training came in really handy years later when we went to Iraq. Train like you fight. Sweat a lot in training so you bleed little in war. Etc.