what's lowest poundage to use mech. broadheads

Discussion in 'Bowhunting forum' started by kirker23, Jul 16, 2006.

  1. kirker23

    kirker23 Junior Member

    I've read that mech. broadheads fly straighter and are more accurate than trad. broadheads.What is the lowest poundage you can use to get the mechs. to work properly.
  2. Dredly

    Dredly Site Guru

    you heard wrong :) - you can shoot just as accurately with fixed as with mechs - and I think its 55 lbs of kinetic energy.

  3. Pinky

    Pinky Guest

    In the IBEP course, it is stated that mechanicals should not be used on bows with less that 55 pounds of draw weight.

    With the new technology in mechanicals....that may be outdated. The mechanicals have came a long way. IMO ;)
  4. bfisher

    bfisher Senior Member

    It's not a matter of poundage. Whether mechanicals can perform well is determined by Kinetic Energy. There is no cut and dry answer about thgis either, but suffice it to say that very few knowledgeable people recommend them for anything less than about 60#. That being said, it comes down to having the proper arrow, too. Something heavy enough to carry some momentum once those blades start trying to punch hide and open up. Then there is the question of how large a cutting diameter they have. Wider cutting heads require more energy than a narrow cut. Blades that slide back, like Snipers or Tekan's don't require as much energy as those that flip back.

    It's pretty well accepted that it takes about 25% of the arrow's energy to punch the hide and flip those blades to the open position.

    Then ther is the problem of quartering shots where , if one blade hits at an angle, it may cause the arrow to cartwheel instead of just shooting straight through. This can greatly impede penetration.

    As you can see there are too many variables to make a blanket statement about just what poundage is required. I'd say if you want to be ethical about it then settle for no less than 60#. And that doesn't mean you should overbow yourself just for the purpose of shooting mechanicals. That surely won't help you at all.
  5. BowhuntnHoosier

    BowhuntnHoosier Bisquit.......


    This is what I have been told also 55# but I really like my MUZZY'S so have never experimented with expandables.
  6. Pinky

    Pinky Guest

    I suggest that everyone read bfisher's post to the letter. He really makes some good points. ;)

    I am testing my new mechanicals on my 3D targets. Thus far, all is good.

    The only reason that I am now testing expandables is due to the fact that my arrow speed has increased to a point where my "old faithfuls" don't fly well.

    I purchased a new bow and the arrow speeds went up. My hunting shafts are the same, still weighing in at 438 grs. The "old faithfuls" seem to plane some with the higher velocity.

    I agree with bfisher, that the arrow's KE will be the most likely issue affecting the performance of mechanicals on live animals. Along with cutting diameter, and blade configuration.
  7. Home-a-lite

    Home-a-lite Guest

    My previous hunting arrow was 357gr. The bow was set on 69lbs (Mighty Mite). This combination produced 61-62 lbs of kinetic energy. At that time, I used Rocket mechanicals (85gr).
    The deer in North Carolina are smaller than northern deer. These broadheads haven't ever "failed." Broadside and quartering away shots have been pass throughs. I'm gonna type part of this again for a reason.

    Broadside and QUARTERING AWAY shots have been complete pass throughs without ANY failures.

    It's true...one can get a fixed blade broadhead to shot well, but MOST (not all) require additional tuning. I don't have to worry about tuning my Rockets. Wasp also makes excellent mechanicals.

    I will use Rocket Steelhead XP 125gr for elk this September on a 468 gr arrow producing approx. 68lbs of kinetic energy.

    I would shoot whatever you have confidence in through experimenting with your set-up. But hey, I'm not a pro.
  8. JVA54

    JVA54 Member


    Totaly agree kinetic energy is the key 60#+
  9. Dredly

    Dredly Site Guru

    just a side note - if you uped the speed on your bow your arrows may no longer be spined correctly for the bow your shooting now. If you can't get your arrows to shoot right with a broadhead it could be due to the arrows not matching the bow. This can often be seen as "planning" or "not grouping" as the arrow isn't flexing correctly.

    Just a thought. I know my Muzzy's shoot just as well as mechs out to 30+ yards at 270+ FPS. A lot of times Mechs are seen as solutions to other problems, sort of like patching up the whole instead of fixing it. If they fly like your field points but your field points don't fly right the issue isn't with the tip but the arrow :)
    Last edited: Jul 29, 2006
  10. Keith

    Keith Guest

    So how do I figure up KO?

    MY arrow is a Carbon Excel at 7.1 gpi. The arrow is 28 inches long and has a 100 grain point. It's shot out of a 55 pound bow. What is my KO? and is it enough for mechanical?
    Last edited: Aug 6, 2006
  11. Radar

    Radar Story of my life

    Kinetic Energy Formula

    To figure out your kinetic energy here is the formula, you will need to know your arrow speed (AS), your arrow weight (AW).

    AS x AS x AW

    Hope this helps