I had the same problem, I used the Phathead broadheads and out of nine arrow broadhead combo's I only had two that were close. Then I switched to the Rage 100 grain broadheads and now I'm shooting three inch group's out to 100 yards.
I did fire two non practice broadhead shots (one at 30', one at 60') at my broadhead target and they fly and open great. I was able to remove the heads because they came out the back side of the target two inches. (just replaced the breakaway washers). As a note I also use the Firenock's, the combo does shoot differently then a standard arrow. I just picked the six that shoot consistently and I'm all set.
Last year I took a 275 lb. eight pointer at 77 yards, the arrow went through him with so much force it hit a rock, flew 30 feet in the air and 50 feet past the deer. The deer didn't move, I thought I missed. While reloading for a second shot he crumpled in place. So I know this combo is deadly at long range.