Stay away from BrassMaxx .40 ammo for CM40

I bought the BrassMaxx .40 at Walmart because that is the only .40 ammunition I could find locally to break in my new CM40. I had bought two additional 6rd finger extension magazines as well. First session my brother in law and I fired about 80 rounds or so. Every magazine had at least 1 but often times more FTFs. Before my second session with the CM40 I bought a 100rd box of Federal American Eagle at my local gun shop. I fired 3 magazines with these with no issues. I then loaded one magazine with the BrassMaxx and sure enough FTF. Fired the other two magazines right after with the Federal and no problem. Used up the rest of the Federal box and I did have one FTF with it but that is all. I used some of my buddies Winchester white box with no problems and then ran through about 30 rounds of Federal HST HP for carry and those had no issues either. I had both my buddies use the BrassMaxx in their guns (M&P and Shield) and it worked fine for them.

A few things I noticed after cleaning it up was that there are several nicks on the bottom edge of the slide in front of the slide hold open notch. The other thing that concerns me the most is the polymer rails the slide attaches to. They seem pretty beat up already and material has been shaved off of them both times I used the gun. I had to pull some of the shavings off when I was cleaning. Is this normal? She still goes back together and functions properly but visually those rails already look like crap.

My 2 cents.

Thanks,
Mike