Recoil spring paint

[attrapereves]

Any idea what the paint colors mean on the M&P recoil spring assemblies? Any reason for it? On my M&P45c, the barrel is speckled in red paint after shooting sessions because of the paint. Kind of annoying, but I guess it will eventually stop.

 

[Rastoff]

The paint is so it's easy to tell them apart. I don't have a 45c so, I didn't know they had paint on it. But the 9mm is blue and the .40S&W is green. My .40c is yellow.

Each color has a different spring weight associated with it.

Yes, it will eventually stop, but it won't hurt to take a brush to it to speed the process. It annoys me as well.