I would bet money the Leade (throat) is not completely smooth and polished and/or it is too tight and needs to be opened up .
It sounds as if the final finishing throat polishing wasn't done completely.
Have a gunsmith look at the throat and finish the job.
Don't do it yourself because it's easy to ruin a barrel if you don't have the correct tools and knowledge.

When pulling bullets , seat the bullet a little deeper , just enough to break the crimp ...with the hold on the bullet by the case broken it becomes much easier to pull them ...usually 3-4 firm strikes but not pile driving hard blows .
Gary

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