Rate Of Fire

The M60 machine gun has a cyclic rate of fire of about 550 rounds per minute, no selective fire.

That's a GURPS RoF of 9!.

I just watched a video about the gun.



It tells us that sustained fire is 100 rounds per minute (GURPS RoF 2!) and the rapid fire rate is 200 rounds per minute (GURPS RoF 3!).

They say the barrel should be swapped every ten minutes at the sustained rate and three minutes at the rapid rate.  Put another way, that's every 1,000 rounds at sustained and every 600 rounds at rapid.

My Feb 1984 and Oct 1964 TM 23-67's both say to change the barrel every ten minutes at sustained, 2 minutes at rapid and 1 minute at cyclic.  That's every 1,000, 400 and 550 rounds, respectively.

A RoF of 2! seems really low.  But what it works out to is more like a burst at the full rate of 9! then five seconds of not shooting while you assess the effects of that burst, aim, change targets, etc...  Rapid is a full turn at 9! then three seconds of not firing.

The TM on the pig even says the most effective rate of fire is 6-9 round bursts with 4-5 seconds between them.  60 to 108 rounds per minute.

Based on experience with actually playing the game, the 600 turns that's ten minutes, 180 turns that's three minutes , 120 turns that's two minutes or even the 60 seconds that's 60 turns; it's just never going to happen in "combat time".

The 23-67 says the basic load is 3x 100 round belts for the gunner, 3x 100 round belts for the assistant gunner and 3x 100 round belts for the ammo-bearer (if any).

So a two man crew is lugging just over a minute of shooting at the cyclic rate, but almost ten minutes at the recommended sustained rate.  So, if you're doing it right, change barrels when you and the assistant run out of ammo!  One of you can change the barrel while the other is screaming for the ammo bearer to bring another belt (he often wanders off during combat because of ephemeral things like "orders").