Hmm I am puzzled
don't you use a Bronze brush?
I always wet a bronze brush with P-H 009 and srub the barrel then let it sit for a few minutes then do it again. This removes the hard glazed powder residue letting the bore cleaner work on any acculmilated copper fouling. Then push clean patches through to remove the bore cleaner. It normally takes about 4 patches but if you scrub the last patch back a forwards in the bore you will make some dirty streaks on it.
As for the .270 jag being tight with your patches
been there myself
I now used Napier Rifle clean which is a blue coloured fibre on a roll in abox which you cut off to the correct length for each calibre and it works a treat
. Oh I use Parker-Hale rods and jags/brushes.