Bore swabbing between shots

[Skinny Shooter]

While shooting my squirrel rifle and musket I found that light charges foul less than heavy charges and patch thickness plus ball size also figures in to how hard subsequent balls get seated.
Aways back I ordered a TVM rifle and not wanting to have to spit patch after a few shots, I had a Colerain swamped barrel installed. http://colerainbarrel.com/

While at the range last weekend using 90 grains of FFg, .020 patch and .530 ball I shot about 30 rounds without swabbing the bore.
Haven't tried more than that cause thats usually all time allows when at the range.
Oh yeah, I've noticed humidity will also factore into how hard a ball goes down the tube.