FN, Over the years we have shot quite a few elk..many with the cup and core bullets like Serria 165 grain HPBT, even some 150 grain Nosler BTBT...when punched through the lungs from the side DEADLY, as you well know...but a bit of an angle and big trouble can occur...I am sure as you well know...the only elk I lost took a hit behind the should from a 165....I wanted to punch the shoulder due to the angle, but was afraid of bullet blowup as it was fairly close...as a result, I went behind the shoulder, and a slight angle caused me to only catch one lung...disaster...the elk got off and was ruined by the time it was located...had I hit both lungs, it would have been over, BUT if I had used a Nosler Part. or similar slug, and punched the shoulder and lungs it would have also been over...after that , I have pretty much stuck with Nosler Part. Even on mulies, a chest hit might let them run a bit, but there was always an excellent blood trail. Over the years we have even shot some whitetails with 200 grain Nosler Part. they did an excellent job...little blood shot meat, exit holes, even at bad angles, great performance...I have tried the accubond in my .340 while it lost considerable wt. from 225 to 90 grain, the core was still in the jacket...may give these a try this year...Also dropped an elk with a 200 grain Acc. from a .300, but had the elk processed for a friend and was unable to recover the bullet....When I was in Africa, my pal shot a .338 with 250 Nosler Part. we recovered several of his bullets...I shot a .300 with 200 grain Part...the only slug I was able to locate that did not pass though was from a Wildbeast...hit the left shoulder and the 200 grain Nosler was found in the right hip...penetration..I did weight it at the time and have it somewhere in the reloading room, but performance was excellent...
As you said on game bigger than deer/antelope premiums are cheap insurance....Had Elmer started with Noslers, he might NOT have loved big bores sooooooooooooo much!!!!!
Just got home from a trip to Washington, and fished in Montana...beautiful trout waters...never saw an elk...tons of whitetails, and a few mulies...beautiful state..