When SCJ429 said to baby the barrel he means dont over heat it or shoot really hot loads in it to start
this is a good read by Gale Mcmillan from Mcmillan stocks/rifles ect
https://www.6mmbr.com/gailmcmbreakin.htmlwhat I believe is that every rifle is different and so is every barrel, treat everyone differently
the problems that I believe cause the fouling is burrs, either on the lands from the barrel being made or from chambering
you need to look down the muzzle and see if there is any copper present after shooting before cleaning
dont just look at the colour of patches
IMHO there is no need to clean if the barrel has no copper
but when copper is present clean the bore till you can shoot quite a few shots without the bore coppering up
I have seen factory barrels take up to 80 shots before they would settle down but also seen more than one tikka be run in after 3-5 shots
tikka barrels are hand lapped but that's not to say a hand lapped barrel wont have burrs,
the polishing from lapping may not get it all out and the burr may be from chambering
there is nothing wrong with leaving your solvent in overnight or even for a couple of days
its not acid just keep brushing and wetting it down every few hours then leave it sit overnight and patch it out in the morning
the way I use solvent is to apply it on a nylon brush and give it a scrub
I use patches to get the crap out
“If you do not read the newspapers you are uninformed. If you do read the newspapers you are misinformed”. Mark Twain