RE: 100 gr. broadheads big enough for elk?
 

no problems hammer...I got my elk this year with a 100gr wasp 3 fixed blade. Great penetration and the wasp totally destroyed anything in its path, elk ran 40 yards. I snapped a rib off and the boradhead was still stickin out the other side of him. So i believe a wasp IS capable of doing the job.

RE: 100 gr. broadheads big enough for elk?
 

Absolutely they are big enough. I use 125gr muzzy or nap thunderhead myself. The key thing on a elk broadhead is the tip. It needs to be a either a fine constructed chisel point like the old bear broadhead or tips with the hollow ground point or longer three sided points. Definitely stay away from the ones that open on impact. ooohhhhhhh those are not good on elk. Rips the blades right off.

Probally the best elk broadhead going for their heavier structure is Muzzy, that longer hollow ground point allows for the point to bust a rib into before the blades come in contact with the rib. It also drives into the animal straighter than the old round pointed broadheads.

RE: 100 gr. broadheads big enough for elk?
 

I use Easton XX-78 2219 arrows & Muzzy-125gr broadheads.
Your set up should work just fine. If you do decide to change anything? I would go heavier.

RE: 100 gr. broadheads big enough for elk?
 

You should have no toruble with your 100grainers its not what you shoot its where you shoot it. good luck