Heavier Recoil Spring & Carbon/Soot

[SamC]

I changed out the recoil spring in my 10mm DW Razorback from the factory 20 lb spring to a Wolf 22 lb one without changing out anthing else. I did it to to help protect the slide/frame from excess battering.
I fired 100 rounds with the new set up tonight without incident.
The only thing I noticed was at the end of the night the muzzle was plastered with carbon/soot. Last week I shot the same Remington 180 grain ammo using the factory spring and didn'the notice the muzzle and chamber area being that dirty. Would the heavier recoil spring by changing the slide speed cause that or maybe the ammo is just inconsistent with the last 100th rounds of the case burning dirtier?

[my_old_glock]

I don't know. Maybe when the slide is opened sooner it acts like a bore evacuator on a tank barrel.

Theory/WAG: When the slide opens up with the lighter spring, the momentum of the escaping gasses pulls clean air through the back of the barrel and out the muzzle carrying carbon soot with it. If the slide is left closed there is a vacuum created in the barrel which pulls soot and carbon back towards the muzzle which deposits on the slide.

https://en.wikipedia.org/wiki/Bore_evacuator