That is a popular cartridge and it will get you out to 100 yards in either rifle. The Ruger will probably cost less than a decent M16 clone. Now, some M16 clones do shoot surprisingly well. (Not my cup of tea after military years tho.) The thing about a bolt rifle is that if you should ever need more accuracy, it will be there. You will probably struggle in the accuracy Dept with a Ruger. The 223 should get out to 300 in a decent piece, unless the wind is bad.