My fiancé took red stag at 120 yards with a 300WM(yes she does not mind shooting 300WM and her hunting gun is only 7lbs scoped, she also shoots my Christensen Arms 338LM which is just 9 lbs scoped with bipod). She had 150 Grain GMX Horandy in it.
He started walking away so I put 3(THREE) 178gr AMAX from my 308 in to the base of his neck. He kept walking until last one broke his vertebrae. Even than he was thrashing around for 5 minutes.
Her shot placement apparently was perfect - Both lungs and heart. GMX did job OKis - expanded and animal would have eventually died.. My AMAX sucked - none of them expanded and first 2 just missed anything major in the neck. Strangely enough same 178gr AMAXs were devastating on wild boar dropping Miss Piggy in their tracks and
doing tons of internal damage.
Lesson learned - big stout animals do command some firepower but bullet choice is critical. Make sure your Berger expands well.
Do not attempt long range shots and let wounded animal get away.
Or get really nice muzzle break and recoil pad and have your wife actually enjoy shooting 300WM like my lady does.
As always - bullet placement is critical. Go for heart/lung shot - without fragmenting bullet neck shots are iffy on large animals. If you don't hit the shoulder 6.5CM would take Elk down - no lungs = can't breathe