I crunched the numbers on my balistics calculator, here is what I got.

You are dogging the 338. And you jacked up the B.C of the Speer 165gr SPBT.
Here is the real B.C. for that bullet.
30 Spitzer SPBT-Soft Point Boat Tail
Diameter: .308"
Weight: 165gr
Ballistic Coefficient: 0.477

All rifles are different but I can tell you my 338 does shoot better the hotter you load it. The actual max load for the 338 is 3340fps. with a 180 Accubond. Now like I said before I have never shot a 180 in my rifle so it might not shoot worth a crap. But I will be tryng it, I havnt found a bullet yet that doesnt shoot extremely well in it.

300 win mag. with corrected B.C. of .477
Muzzle -2.5 Infinity 3120 3566 73.54 0.000 0.0 NaN 1240
100 0.8 -3 2917 3117 68.76 0.099 0.6 2 1014
200 0.0 0 2723 2717 64.19 0.206 2.4 5 825
300 -5.5 7 2538 2359 59.82 0.320 5.6 7 667
400 -16.4 16 2360 2041 55.64 0.443 10.2 10 537
500 -33.6 26 2191 1759 51.64 0.575 16.5 13 429

338 with actual speed. for the 180 Accubond with a B.C. of .372
Muzzle -2.5 Infinity 3340 4458 85.89 0.000 0.0 NaN 1811
100 0.6 -2 3069 3763 78.91 0.094 0.0 0 1404
200 0.0 0 2813 3163 72.33 0.196 0.0 0 1082
300 -5.0 6 2572 2643 66.13 0.308 0.0 0 827
400 -15.3 15 2344 2196 60.27 0.430 0.0 0 626
500 -31.9 24 2128 1811 54.73 0.564 0.0 0 469

The 338 is flatter, not by much but it is flatter at 500 yards, but like you and RR both stated wind will play more of a role on the 338 because of B.C.

By the way, who uses a 165gr. 30 cal for elk? Isnt that a deer bullet? I use that bullet in a 308 for deer.

When I make it home I want to check the 200gr. Accubond, not as fast but it does have a better B.C. might be a better choice in the 338.