I've used mechanicals in the past and I don't use them any more. I just prefer the fixed blades better because they get better penatration. I've never lost one with fixed blades, I have with mechanicals. I like the montek G5 and I also use the crimson talons.
Never have, and I would not! There critters are very thick and tough, you need all the penetration you can get. You want a bear down as quick as possible, dragging these things out of the wood is not like deer it is a TON of work.
If I ever see the size bear I want to shoot-over 250 here in GA-I will be letting the Spitfire fly at him/her.
No doubt in my mind what that broadhead will do out of my setup.
But, it is all about confidence. Shoot what you think is best for YOU.
I would not recommend them out of a light poundage/short draw bow.
I've shot one with a rocket sidewinder, the bear went less than 30 yds. I hope to put a rage in one this year, in the right spot any broadhead should do. In my experience, bears really aren't all that tough when shot. I've had spike bucks go way further shot good than any of the bear kills I have had or seen.
I shot one this summer with a Trophy Ridge undertaker 3 blade and it died running. My brother shot one on the same trip to canada with the undertaker 3 blade and it ran 15 yards and died. We ended up taking four bears with the undertaker and they all died with in 50 yards. I have no problem letting a bear suck up a mechanical.
The real question is ''why am i wanting to use a mechanical?''
''Because they fly like field tips.'' is the common reply. If your bow is properly tuned you can stack Magnus stingers with your field points at 60 yards. I prefer a good compact 3 blade like g5 striker or Muzzy MX3. Penetration gets no better than a fixed blade.
The secret to perfect bow tuning is: (drum roll)
1. Paper tune
2. Walkback Tune
3. Broadhead Tune
in that order. Take it as the gospel from a guy who hunts with a bow from small game season to turkey season.