Wouldn't plasama bolt hurt like hell since they can burn through human flesh easily then bullets?
That's where the shock comes in.
Then the enemy would still be alive but is in shock or they die completely of shock.
Then the book wouldn't have the catch phrase "Its the 25th Century but the marines are still looking for a few good man..."
It would be "Its the 4th Century but the marines are still looking to kill a few man with sticks and stones..."
I hope this doesn't sound pathetic.