Major fouling. What gives?

[matsaleh]

Took my S&W 6906 9mm to the range for some overdue practice. I shot about 125 rounds of Winchester White Box target FMJ (115 gr. - the stuff that comes in 100 rnd boxes for $11) from Wally World, and about 25 of the WWB Personal Defense load JHP (also 115 gr.). Of the FMJ, I finished up an old (few months, that is) box I had sitting around, and also a brand new box I just bought today. The JHP I also bought today.

During the session, I had two failures to eject out of the old partial box of FMJ. This is rare for this gun. No other failures on any of the other ammo. However, when I finished up, I noticed a lot more residue around the bore and muzzle of the gun. When I got home and took it apart to clean it, there was more gunk and fouling inside than I have ever seen. It took some real elbow grease and a wire brush to get it out - it was not just the thin film I usually get, but almost a baked-on, thick substance that you have to kind of chisel off with toothpicks and wire brushes.

What could have caused this amount of fouling in only 150 rounds?

This is my current carry gun. I bought it used as a PD trade-in, and it has been very reliable so far. The gun has exterior wear, but bore is clean and a recent detail strip revealed no issues or undue yukkiness or gunk inside. I religiously clean the gun after every practice, and periodically when it's just in the holster.

I know the Winchester White Box stuff is cheap, but I haven't had any problems with it before or noticed major gunkage from it. I don't recall having trouble with the first 3/4 of the old box, either.

Thanks to anyone who has ideas about this.

 

[fastbolt]

We've used the Winchester 147gr JHP's, packaged as the Personal Protection line (USA9JHP2), as training ammunition for the last couple of years. It is the DIRTIEST ammunition regarding fouling which I've fired in many years ... reliable and accurate, sure, but dirty. Almost as dirty as the Federal American Eagle stuff we used for a while. It's the same story in the .45 & .40 S&W Winchester "white box" ammunition we've used. There's probably a reason it's so affordable, you know ...

The Remington Express line of "inexpensive" pistol ammunition often seems to leave less residue after extended shooting sessions ... as do the more expensive lines of any of the manufacturer's ammunition ...

Heck, after becoming accustomed to the "popcorn" of the older 2400 powder, and the "oily", sticky residue of Unique powder, when I was a reloader more 20+ years ago ... I feel like I'm shooting reloads again.

Seriously, the only thing that really annoyed me was when I was shooting a lot of the Federal American Eagle .45 hardball we ordered once ... and I'd find the occasional large, "fluffy" flakes of black goo lodged in the working parts after a range session ... Yuk ...

The sacrifices we make for shooting "less expensive" ammunition ...