I used it once on my Steyr after trying the pull-through and the cleaning pellets. I bought the rifle secondhand and it was already 2 yrs old. The groups I was getting were not what I expected from a steyr and after stripping and cleaning, the brass brush was my last resort. I was even thinking of buying a new barrel for it, so I went ahead and used the brush. It did make a noticeable difference to my groups so perhaps I had some serious build-up in there. i was very careful not to push too hard with it and i covered the transfer port. It has been much better overall since using the brush.
I was just wondering wether or not I could do this regularly without damaging the barrel. I usually clean mine with the pull-through every 1-2 tins of pellets which is roughly when my groups start to shotgun a bit.
Atb
Peter