"The 308 shoots flatter"--- Not exactly. Below is the chart for the 180 grain 308 partition, the 210 grain 338fed partition, and the 180 grain 338fed accubond. (From Federal web-site). 2nd chart is energy. The 180 grain 338 is actually flatter than the 180gr 308 and the 210gr 338 is the same. If this is a mostly elk cartridge, go for the 338fed. Not only is the trajectory the same with a 210gr partition, there is the matter of larger frontal area. I have a 338fed in a Sako 85 and love it. I use the 200gr interlocks on deer and hoping to some day use the 210gr partition on elk. If you reload, brass is cheap and everywhere (308 brass) and there is more than enough choices of bullets in 338 calliber. The price of 338 bullets compared to 308 bullets is about 2$ more for a box of 100. If you do not reload, you may want to consider a 308 but I defenetly recomend the 338fed. Also, I know you said Kimber, but you can get a Sako 85 in 338 nib for $750 here:
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=167773991
I got mine from here and it is the real deal. Apparently Sako way over-estimated the popularity of this cartridge and are trying to get rid of the old stock.
Load No Caliber 50 Y 100 Y 200 Y 300 Y 400 Y 500 Y
P308E 308 Win. (7.62x51mm) 1.1 2.3 -9.4 -26.9 -54.7
P338FB 338 Federal 1.1 2.3 -9.4 -27.3 -56.3
P338FA1 338 Federal 0.8 1.8 -8.2 -23.9 -49.3
Load No Caliber Muzzle 100 Y 200 Y 300 Y 400 Y 500 Y
P308E 308 Win. (7.62x51mm) 2640 2278 1957 1672 1420 1202
P338FB 338 Federal 3225 2712 2266 1878 1545 1266
P338FA1 338 Federal 3201 2672 2214 1820 1482 1199