I would say that you have already set a good base up. if you already have 223 ammo on hand then that is a good caliber to go with to develop your shooting skills as the low recoil will make it easier to avoid developing a flinch. I would recommend a weatherby vanguard in 223 with a cheap Redield or Nikon 3-9x scope. you really need to develop your skills close and work out to range gradually. your best thing to focus on now is to get good at ranges within 300 yards and then work out.
you can worry about more powerful long range guns once your skills have been honed.
ignore my complete lack of capitalization. I still have no problem correcting your grammar.
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