i was goin to use the shockwaves last year but i ended up using magnus stingers instead, i did practice with one though and it would hit right with my fp with no other tuning, i do now that they prolly wont last through heavy bone, the blade will sheer off, i wouldn't worry bout them not openin, i shot spitfires two years ago, i use an 85 grain spitfire on easton a/c/c, finished wieght of around 360 grain. out of a 55 pound bow at 29in draw, and they performed flawlessly to take my first deer. you could see where all three blades had opend on the entery wound, it is a personal choice for u if u want to shoot them shoot them if u think u would feel better shooting fixed blade broadhead go that route it is all a matter of choice, i have used both succecfully and would go either way when choicein,

good luck