Rem.Ballictics showing up wrong??

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Ageo308, Dec 15, 2004.

  1. Ageo308

    Ageo308 Active Member

    Messages:
    25
    Joined:
    Dec 10, 2004
    Hi Guys i need to confirm this.

    Im studying the 25/06 bullets:

    SHORT-RANGE¹ TRAJECTORY*
    Cartridge
    Type Bullet 50 100 150 200 250 300
    Remington® 100 PSP CL 0.0 0.5 zero -1.7 -4.6 -9.1
    Express®
    (B.C 0.292)
    Remington® 120 PSP CL 0.1 0.6 zero -1.9 -5.2 -10.1
    Express®
    (B.C 0.362)
    Premier® 115 PSP CLU 0.1 0.6 zero -1.9 -5.1 -9.9
    Core-Lokt® Ultra
    (B.C 0.380)

    Now i read the The higher the B.C the flatter (accurate) the bullet will be. 257" (.25) 100 grain, SD .216
    .257" (.25) 115 grain, SD .249 So the higher Grain obviously states better S.D - but in the above chart it shows the Express 100grn which has *less* B.C and S.D is more flatter than the Core-Lokt 115grn which has higher B.C & S.D

    Sorry about the jargon but im confused, remington is saying 1 thing and chuck hawks is saying another.

    If some1 could rectify this it would be much appreciated.

    thanks
     
  2. wapiti13

    wapiti13 Well-Known Member

    Messages:
    521
    Joined:
    Mar 8, 2004
    Remember, there are three kinds of lies: Big lies, Little lies, & Statistics. SD is the ratio of bullet's weight in pounds divided by its diameter in inches. A higher SD "usually" indicates a better chance of penetration, since more weight vs diameter means a longer bullet. BC is the ratio of the sectional density of a bullet to its coefficient form. BC represents the projectile's ability to overcome the resistance of the air in flight.
    Two bullets, same diameter and weight, one round nose & one spitzer; both have the same SD. Obviously, the spitzer will have the higher BC. What looks funny in ballistic charts is comparing apples & oranges. If bullets of different BC are shown as in your example, you MUST compare the same velocities to compare apples to apples. Lighter bullets go faster, heavier bullets go slower. Looking at ballistic charts you usually have different velocities compared head to head. The "lies" of statistics. Go to a ballistic program on your computer and compare two BC at the Same velocity and you will see a difference. Comparing two bullets of the same weight from two different manufacturers will often open your eyes unless both BC are the same. The Winchester Failsafe is a good bullet, but it has a low BC. At long range, trajectory and energy (factor of weight & remaining velocity)really suffers for the Failsafe.
    Hope this helps! /ubbthreads/images/graemlins/cool.gif
     

  3. Ageo308

    Ageo308 Active Member

    Messages:
    25
    Joined:
    Dec 10, 2004
    wapiti your the man.

    thanks