Thread: Getting ES down with 223

The crosshair on the Nikon currently mounted to my 223 is quite thick and pretty much obscures those dots. I used the BDC to aim at the dots below, so blowing out the aiming point was not an issue. The WSM group hopefully demonstrates that I'm not completely useless behind the trigger (rifle is not zeroed for that load). With a beefier scope and a properly bedded rifle, I'd expect those 223 groups to shrink considerably and I understand *why* they are a bit sub-par currently, so that's OK (the two left hand groups are around 0.8" and the right hand group is around 1.2").

For the purposes of this exercise though, I am more concerned with the velocity data. I'd expect that smaller cases like 223 will inevitably have proportionally higher ES/SD than larger cases, as a similar variation in charge weight or case volume is going to be a greater percentage in terms of change on a smaller charge or smaller case - which effects pressure more thus effects velocity more. Even so, the 223 is approx 25gn of powder vs the WSM's 65gn, that's only 2.6x the capacity in the larger case, and charges are accurate to the kernel in both... yet there's 7x the ES/SD in the 223.

I know we are also dealing with higher velocities in the 223 too and that say a 1% ES from 2800ft/s would be 28 vs a 1% ES from 3300ft/s being 33. That still doesn't account for enough. With the 69gn load doing 3120, the ES is 15-20ft/s, so the 223 clearly is capable of it... just these effing 55gn bullets aren't getting the memo.