With eva+eva extend is relative easy. I wanted to do it with melee first and then take my loved lbgs and give the try x) GS is the strongest weapon/hit, that´s for sure, and land a charge lv3 on tigrex head is so easy when he turns to you but... i´m not used to greatswording tigrex xD. There´s a vid on youtube from a guy with a top raw and sleep GS who do a 140 tigrex in no time, watch for it ;)