[mike benedict]

Since the M&P design is pretty much like a Glock I would believe that the guide rod replacement cycle would be about the same.

At the Glock Armorers school i was told to replace the recoil spring assembly every 5,000 rounds in a 9mm and 3,000 rounds in everything else.

So that is my plan for now

 

[mike benedict]

You probably won't see an malfunctions until the spring is totally shot but you are risking frame damage.

Glock did not recommend changing springs until they started to see frame damage and broken rails on the .40 cal. pistols.

Now they give you a sack of springs and tell you to replace them often.



Springs are cheap insurance

 

[mike benedict]

Glock springs are pretty much the same except the Glock units have a plastic guide rod

 

[mike benedict]

you don't

Just order a new one and replace the whole thing