I hunted for years with thunder heads and had no problem getting them to group with field points out of my well tuned bows. This year I'm using the G5 montec heads and they group with my Field point out to 30 yards any way and cut the vanes right off each other and if I shoot a field point it go right into the middle of the group out to 30 yards. Done it a hundred time this fall getting ready for bow hunting. I try ed mechanicals for about tree years and had bad luck with them. I thought the penetration sucked. They didkill things but, just didn't penetrated like I like to see.