You do realize that you are pushing LEAD down a barrel!
O.K. I had to say that...sorry!
I agree with the cleaning issue, you would probably do more to damage your barrel with misuse of cleaning agents and stiff bronze brushes that with your ammo.
I can say that I have shoot over 600 rounds of 9MM as fast as I could load into my mags and the barrel still looked great before I cleaned it. (Very dirty but looking good)
When I was done I had a fun time getting all the built up lead out of the rifling.
What I was surprised by was how much copper fouling was found
Under the lead.
Previous owner of the upper did not clean it correctly and it was one blue patch after another till the barrel was spotless.
Clean your upper correctly and you will get a hell of a lot of use out of it.