Bolt with Spring?

[Jamers99]

Looking at the owners manual it shows this.

https://docs.google.com/file/d/0B1VQ8P-JiKDaeGQzOF81OVV3UEk/edit?usp=sharing

My M&P15 Sport does not have this spring. Am I supposed to?

 

[Lee in Quartzsite]

Mine does, but it's the piston model, M&P15PS.......

 

[MichiganScott]

The bolt shown is for a piston AR like Lee said. Notice that there are no gas rings. So no, your Sport is not supposed to have that spring.