Was hoping to hear from someone who has used nap's spitfire mechanical heads on bear and what they thought of them? I used thunderheads about seven years ago and got a complete pass thru on a 240lb. bear.I am now soon heading out for another bear hunt and all I have are the spitfires.Should I spend another 30 bucks and get the thunderheads or will my spitfires that I use on deer do the trick? Thanks in advance...Hugh