My sons first elk was at 300 yrds. lazered, broadside, 3 shots , 2 pass threw,243 100 gr. spire. Elk body was one of the larger I ve seen, packed out about 100. bull went about 20 yrds.Bullet performance could still be the biggest determining factor of whether the elk drops or runs off. Small caliber bullets are still marginal in performance with the exception of the mono bullets like the tripple shock and e-tip. This year while hunting antelope, my hunting partner shot an antelope buck at about 125 yards with his T/C 243 with a hornady interbond bullet leaving the muzzle at about 3500 fps. The bullet hit the antelope behind the shoulder and the frontal area exploded on impact making a very large surface fleshwound with the remainder of the bullet only achieving marginal penetration after the bullet changed direction. The antelope ran far enough that it had a chance to lay down in the brush out of sight. When we jumped it it took off like it wasn't even hit. Bullet performance failed. That bullet wouldn't have had a chance of killing an elk.