Cotton flannel is what I was using. I've got an old Queen sized flannel bedsheet that should last for a lot of cleanings. The way I did it was push it down with the jag, then pull it out, turn it over and use the same one for a second run. Then load. It kept shooting just fine. I was having problems with the sun on my sites again and couldn't find any shade to alleviate the glare, so my accuracy wasn't quite like the other day.
I was happy with the shim I had put in the lock, as it worked perfect, no malfunctions this time.