I would take a Hornady interlock over a berger , but that is just me.
Well at least you'd be using an actual hunting bullet.
There's a good reason premium bullets with a parition or bonding (or both) in heavy for caliber weights are recommended. Elk are big bodied animals, and to ensure your bullet makes it through the vitals and gives you a nice exit wound you need a heavy bullet and you need that bullet to retain the weight as it travels through the animal. The interlock may do that - the lock ring is an attempt to prevent bullet failure. It may not. An Accubond will do much better typically. An A-Frame will basically always work, but you need to make sure the impact velocity is high enough it expands.
The Berger bullets will either not expand at all, or fragment in the first few inches (which you get appears to be random). In either case you're not ensured much damage - if it doesn't expand you get a pencil thin wound, and if it does the depth of penetration is only a few inches and damage may well be contained to one lung. Those kinds of wounds will absolutely kill the animal, but it may very will die hundreds of yards if not miles from where you shot it, and in either case there's likely to be little or no blood to track (no exit wound, or one that seals up).
The Berger hunting bullets are junk, plain and simple. Those who advocate them are fools.
