Wayne the DPMS ORACLE 5.56 should be able to handle US and foreign manufactured ammo with no problems. The only ammo I would recommend against is steel case ammo (Wolf brand etc.). For home defense the distances are short so accuracy is not critical. Just about any brand or style should work. I would buy a couple different brands with 55 grain bullets in your price range and test fire them. 5.56 ammo with 55 grain bullets will give you the widest verity of brands, bullet design, and price to choose from.

Hey Wayne, you should be good with both Most issues might arise from steel cased ammo. but american eagle, winchester and federal have all worked fine for me.

Home defense ammunition would be a good soft point round like : budsgunshop.com/catalog/product_info.php/cPath/656_2081_10000601/products_id/714014129/SSA%20556NATO%2063GR%20SP%2020/400/ ---- budsgunshop.com/catalog/product_info.php/cPath/656_2081_10000601/products_id/59189/Federal%20F223FS1%20Fusion%2020RD%2062gr%20223%20Remington/ --- budsgunshop.com/catalog/product_info.php/cPath/656_2081_10000601/products_id/15461/Hornady%20223%20Remington%2055%20Grain%20Personal%20Defense/

Home defense ammunition would be a good soft point round like : budsgunshop.com/catalog/product_info.php/cPath/656_2081_10000601/products_id/714014129/SSA%20556NATO%2063GR%20SP%2020/400/ ---- budsgunshop.com/catalog/product_info.php/cPath/656_2081_10000601/products_id/59189/Federal%20F223FS1%20Fusion%2020RD%2062gr%20223%20Remington/ --- budsgunshop.com/catalog/product_info.php/cPath/656_2081_10000601/products_id/15461/Hornady%20223%20Remington%2055%20Grain%20Personal%20Defense/