For future reference, definitely keep the Kroil advice in mind, and also the product called Break Free.
Next time let it soak in at least overnight.
I was given a beatiful Savage Model 99 years ago, and only after a gunsmith told me it was a take-down model did I try to get the barrel off. It took 2 days of a good soak in Break Free but it did come off without undue effort.
And as said earlier, Kroil is also a very fine product. But in stubborn cases don't be in a hurry ... give it 24 hours ...