Originally Posted By: Jeepdude1987If your talking long range at 300-500yrds I would probably go .243, but if you want to shoot longer than that I suggest you look at a .260rem.
They use the same parent cartridge (.308win/7.62x51NATO), but the .260 is a the clear winner in real long range scenarios. .243 is going to shoot real flat out to the 5-600yrd range with light projectiles, but those bullets have very poor ballistic co-efficients and bleed velocity quickly. The BC's on the 6.5mm bullets of the .260 just keep chugging along because they have great BC's.
Well of course high BC 6.5mm bullets will outperform low BC 6mm bullets, but you are comparing apples to zucchinis. Lets compare apples to apples. (Assume 100yd zero, 3163' el., 45 degree F)
A .243 shooting a 105 gr. A-max (BC 0.500) @ 2800 fps has an initial energy of 1827.8 ft-lbs. @ 1000 yds with a 10 mph crosswind the bullet drops 323.1", drifts 82.1", has 431.8 ft-lbs of energy and is traveling 1360.9 fps.
A .260 shooting a 140 gr A-max (BC 0.550) @ 2700 fps has an initial energy of 2266.1 ft-lbs. @ 1000yds with 10 mph crosswind the bullet drops 317.2", drifts 68.7", has 681.1 ft-lbs of energy and is traveling 1480.3 fps.
The .243 retains 23.6% of its energy and 48.6% of its velocity. Bullet drop @ 1000 is only 6" more (0.5 MOA) than the .260 and drift is 13.4" more (1.25 MOA). The .260 retains 30.0% of its energy and 54.8% of its velocity.
So, while the .260 has a slight edge (it has a slightly higher BC with the two bullets compared) it also comes with more recoil and more powder. I would hardly say the 260 is a "clear" winner. Two more clicks of elevation isn't much. Both are awesome cartridges, both calibers have VERY good long range bullets but limiting the .243 to 500 yds is selling it short.
So, to the OP's question, I think the .243 is an excellent long range coyote rifle.