It has the slotted thumbscrew for the action retainer instead of the spring. That is a good thing. You also have the better safety system on the plunger IMO. As far as bullets, I would try the .503's you got. See if they lightly engrave on the way down. My guess is you might want something slightly bigger. In my whites I have not had the best luck with those CCI primers. I like the new Remingtons better.
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Vaporizer wholesale
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Vaporizer wholesale