223/243
The .243 will do everything the .223 will do at 150 yards and better, It retains more energy down range and Is more accurate, and has a much bigger ammo weight selection, most states dont let you hunt with the 223, the .243 is a game cartrige, the .223 is a varmit cartrige, If you are going to shoot junk surplus ammo get a M-44 or a 91/30 in 7.62x54 that will fill your 150 yard gap and plenty more for penny's on the dollar, if you want a great round with a little more flexability get the .243 good shooting ammo for it runs about a buck a round, premium ammo ( ballistic Tip ) about 35.00 a box of 20 rounds, remember ammo manufacturers have already done the math, you get what you pay for, and realalisticly just how much are you going to shoot it anyways, My goal when target practising is to get the tightest group possable, and you are not ever going to do that with cheap ammo, so buy the time you spend the money buying .223 top shelf ammo your just a few dollars away from getting a much more capable round like the .243