Using a barrel vice and correct action clamp, there isnt many barrels that will not come off.
As Muir says, it does help to relieve the material directly in front of the action face on stubborn barrels - I use the lathe, mounting the action in a fixture in the 4 jaw and using live centre on the tailstock, I cut .005" forwrads of action face - this usually relieves sufficiant pressure to allow barrel vice and action wrench to be used withour resorting to heat.
Mausers are a PITA, they have crush fit on a ring within the action the barrel shoulder does little other than support the barrel,,,,,
Remingtons, some Tikka, Sako's, Winchesters, Howa - on all, ive' seen thread lock used - on factory tubes.
Only way to deal with these is gentle apllication of heat - hot air gun is sufficient - once you see the compound "bubble" the barrel will usualy move.
Worst barrel I ever had to take off was a Howa, which someone had kindly overtightened the forwards base grub screw - damaging barrel threads - galled all the way out ,,,,,,,
Eventually made a nice rifle tho - eventually...
Unless you have the correct tools, I wouldnt attempt to remove barrels.