arrows only

I think most of those mechanicals will open on release, due to the speed of acrossbow. Shoot the broadhead that flies best out of your bow, it will work!
If your not in it for the kill, go for the head!

Omegalover

Mechanicals dont necessarily open because of the speed of the crossbow,most crossbows are not as fast as a manycompound bows. There are 5 of us that hunt together during Bow season and 3 of them have faster bows than my Horton, which is rated to shoot at 305 fps. (I have never chrono'd it, but if we all shoot at the same time the other three hit before I do)

I shoot Spitfires and have never had a problem with them. I have never shot a turkey with one, but for deer they work very well indeed.

Dnk

I've had wasp mechanicals open on my Exocet until I used two o'rings. I didn't believe it after reading about it on another forum until I saw it myself. Maybe its because the Exocet is a recurve and the string release is at it's highest weight at that point(I imagine that the bolt accelerates pretty violently), but maybe its because the way the Wasp is made or maybe I didn't have the bolt seated on the string. Who knows, I've not tried many mechanicals but I will stick with the Wasps and two o'rings.