PSE TAC 15/15i Crossbow Ballistic Chart Showing Drop

Discussion in 'PSE TAC 15/15i Crossbow Hunting Forum' started by Len Backus, Sep 10, 2010.

  1. Len Backus

    Len Backus Administrator Staff Member

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    Given a projectile with such a rapidly degrading velocity (400 initial, 232 at 100 yards and 8500 feet), G7 BC's work best. I backed into a meaningful BC by using my field drop figures.

    This screen print shows a comparison between my home elevation of 700 feet vs Wyoming's Big Horn Mountains at 8500 feet. I missed a nice buck at 82 yards last week out there on my first hunt day because I had not yet gotten around to creating this drop chart prior to the hunt. Darn! I corrected my scope mounted drop chart the 2nd day and killed a doe at 72 yards on the 3rd day of the hunt.

    Interesting that either a 1000 ft elevation change or a 10 degree temperature change results in a 2 inch drop change at 100 yards. That is quite a critical factor in the field.

    I wish someone had a downrange velocity that we could use to get a more accurate BC?

    [​IMG]

    Your mileage may vary.
     
    Last edited: Sep 10, 2010
  2. Buffalobob

    Buffalobob Writers Guild

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    I really wish you had figured this out a month ago. It would have saved me a lot of heartache and it would have gotten you a nice buck.

    I got up on the Manti La Sal at 9000 feet elevation with my perfectly field tested equipment (at 500 feet MSL) and could not even hit my target at 100 yards. I had to rework my whole set of sight pins. I nearly wore out a hex wrench on those sights.
     

  3. Buffalobob

    Buffalobob Writers Guild

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    Just one other thing to be aware of- where I practice in Maryland is very enclosed with trees so I never have to deal with wind while practicing. My broadheads have a lot of blade surface and I have straight fletched my arrows so they have no spin. Once you get this combination out into the western open areas with even 5 mph wind the arrows plane off excessively.

    I have reflectched some arrows with about 5 degrees and am going to see if that helps and then I may retest some mechanicals to see if the combination is better in the wind. If that doesn't help much I may go to bigger vanes or to feathers.
     
  4. OkieBowie

    OkieBowie Well-Known Member

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    Pardon my newbie question here, but I am a little confused.

    Trace #1 shows a muzzle velocity of 400 fps with a 425 gr arrow.
    Trace #3 shows a muzzle velocity of 400 fps with a 440 gr arrow.

    Shouldn't the 440 gr arrow be coming out of the X-bow at a slower fps than the 425 gr arrow?

    Wouldn't the 440 gr arrow have more energy assuming it did leave at the same fps and has the same B.C., thus the 440 gr should not drop fps as fast? Granted the air is thicker in the case of #3.
     
  5. OkieBowie

    OkieBowie Well-Known Member

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    Before seeing this comment/question, I had contact PSE asking if they had any test data showing velocities at different distances. I was surprised when they said, Nope.

    Oh, well. If I ever get an accurate Chronograph that will provide readings of PSE arrows shot through it, I plan to create such a table. Thus far, I have been thwarted by one inaccurate Chrono and one that would not provide valid readings (or gave no readings).

    I am looking at buying a Gamma Master Chrony, but I want to speak with the manufacture first, and make sure their Chrony will reliably measure the speed of fletched arrows.
     
  6. khan1960

    khan1960 Member

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    I knew my TAC15i was powerful, but I had no idea it was capable of a good kill at that distance. WTG!
     
  7. rrchcarpenterrod

    rrchcarpenterrod New Member

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    Len,
    Is it possible that the drop results you posted are in centimeters instead of inches? I've been shooting my Tac-15 and if I multiply my results, with 100g broadheads, by 2.54 I am alot closer to your results. My drop when zeroed at 30 yards is about 7" at 50 yards. I have yet to shoot at a distance beyond 50 yds.
    carpenterrod
     
  8. Len Backus

    Len Backus Administrator Staff Member

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    These are in Minutes Of Angle, not inches or CM.