Right, back on track with the thread; as I think we have firmly established what I already discovered - MOST folks can get 13gr of Lil gun in a PPU case.
Now that I have put maybe forty rounds down the barrel, the pits are looking much less pronounced. They weren't too shocking or numerous, but have definately mellowed out now. I can only presume that I have scrubbed the worse of the crud out.
I worked for a farmer in my early teens who was something of a wheeler dealer in firearms, mostly shotgun. He always maintained the best way to clean a barrel was to shoot it. We found an ancient martini actioned 22lr in the back of one of his sheds once, you could barely see through the bore; we rodded it through then pumped a dozen rounds through it in quick succession, she was good to go and we used to plink cans in the farmyard after milking in the summer. God bless him he has passed now, and I hope he is wandering those cloudy fields above, looking to walk up a snipe with his old lab at his heel.