If you already have an ar15 you should consider the Mossberg Mvp in 223. I have one and love it. It is really accurate and has virtually zero recoil. Plus they take any ar15 magazine so you will always have extra mags. Another cartridge to consider is the 300 blackout. Remington makes a bolt gun in this caliber or you can get a handi rifle breakopen single shot for around $250. I have the remington 700 in 300 blackout and I LOVE it. You get a 308 bullet with good killing energy with virtually no recoil. Good for within 200 yds. IMHO I would carry this into the woods over 223. Plus they fit in standard ar15 mags and work with standard ar15 bcg. All you gotta change is the barrel.