I agree with Jim, there would most certainly have to be inconsistency with that method. As for the rest of your questions, there is no way to get the alloy any softer than what the base alloy is air cooled. After such annealing there may be some age hardening but probably not a lot.
If I were to try what your suggesting I would line up the heat treated bullets in a pan such as a pie tin, fill with water leaving the noses exposed and place in an oven at about 400 degrees for at least a half hour, Don't quench, allow to cool to room temp. At 212 degree of boiling water there could be minor annealing of the bases but not nearly as much as the exposed noses.
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If I were to try what your suggesting I would line up the heat treated bullets in a pan such as a pie tin, fill with water leaving the noses exposed and place in an oven at about 400 degrees for at least a half hour, Don't quench, allow to cool to room temp. At 212 degree of boiling water there could be minor annealing of the bases but not nearly as much as the exposed noses.
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