243 is a great round, I wouldn't say best all around. It will definitely kill elk though, no problem...especially inside of 400 yards (which I would bet that >95% of animals taken are within that range). Just put them in the boiler room and trust me they'll go down. While dead is dead, other cartridges are a little better at making that happen faster in a more predictable way on tough critters. Don't get me wrong, the ol' 243 will put the hammer on them, but if you want a little more leeway then you'd be better served by say 6.5 Creed, 260 rem, 7mm-08. All are very low recoil, very handy, have multiple bullet designs which are well constructed with high BCs, and resultant high sectional density=consistent killing capability. You can shoot them well and the bullets perform. Pretty easy to go from 0-1000 with any of those. If you're going to step it up a notch, then I still prefer something with a .264/6.5mm or 7mm/.284 bullet. 7mm Rem Mag will do anything you could ever want it to do. As we age though sometimes recoil becomes bothersome (not that the 7mm RM has much) and would still be served extremely well by the 6.5 Creed, 260 rem, 7mm-08.