,
could anyone tell me the ballistic coefficient and sectional density of the 155gr dyer projectile. i would to like to record them in my ballistic program for future reference in load development.
thanks and v bulls to all
BC and SD of 308
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stu_bear2002
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BC and SD of 308
hi guys ,
could anyone tell me the ballistic coefficient and sectional density of the 155gr dyer projectile. i would to like to record them in my ballistic program for future reference in load development.
thanks and v bulls to all
,
could anyone tell me the ballistic coefficient and sectional density of the 155gr dyer projectile. i would to like to record them in my ballistic program for future reference in load development.
thanks and v bulls to all
Stiller/holeshot .22LR
Bruno mod2(sleeved) .22LR
Rem7(sleeved) 6mmBR and 6mm Dasher
Stolle panda 6PPC
Winchester 101 12g
Bruno mod2(sleeved) .22LR
Rem7(sleeved) 6mmBR and 6mm Dasher
Stolle panda 6PPC
Winchester 101 12g
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Peter Hulett
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From NRANZ
Cheers
Peter Hulett
BJD 155gn 30 Cal
Calculations by K. Sellick
Based on actual measurement.
For comparison only - not
guaranteed to be accurate.
Both projectiles were run
through the same ballistic
modelling program
BULLET DESIGN PROFILE FOR: BJD 155gn 30cal
DATA FOR PHYSICAL MEASURMENTS, WEIGHT, SECTIONAL DENSITY, CENTER OF GRAVITY,
BALLISTIC COEFFICIENT, AND GYROSCOPIC STABILITY
LEAD CORE, JACKETED HP OGIVE RADIUS (CALIBERS):12.0
BULLET DIAMETER (INCHES): .308 CENTER FOR OGIVE RADIUS (INCHES):
BULLET LENGTH (INCHES):1.125 AHEAD OF BASE: .018
BOATTAIL LENGTH (INCHES): .175 BELOW AXIS: -3.504
BOATTAIL LENGTH (% OF CAL):0.57 APPROX CENTER OF GRAVITY (INCHES):
BOATTATL END DIA. (INCHES): .270 AHEAD OF BASE: 0.444
BOATTAIL ANGLE (DEGREES): 6.2 SECTIONAL DENSITY: .233
BEARING LENGTH (INCHES): .370 BALLISTIC COEFFICIENT AT STD METRO SL:
BEARING LENGTH (% OF CAL):1.20 C1= .458 C7= .228 AT 2970 FPS
OGIVE LENGTH (INCHES): 0.580 WEIGHT (GRAINS): 154.8
OGIVE LENGTH (% OF CAL):1.883 OGIVE RADIUS (INCHES): 3.696
OGIVE TYPE: SECANT TWIST RATE FOR STABILITY FACTOR OF 1.5:
MEPLAT DIAMETER (INCHES):.045 13.0 (INCHES/TURN
AT 2970 FPS MUZZLE AND STD METRO SL APPROX WIND DRIFT PER 10 MPH (INCHES):
100 YDS 0.6 200 YDS 2.7 300 YDS 6.2
BULLET DESIGN PROFILE FOR: Sierra 155gn Matchking
DATA FOR PHYSICAL MEASURMENTS, WEIGHT, SECTIONAL DENSITY, CENTER OF GRAVITY,
BALLISTIC COEFFICIENT, AND GYROSCOPIC STABILITY
LEAD CORE, JACKETED HP OGIVE RADIUS (CALIBERS): 8.0
BULLET DIAMETER (INCHES): .308 CENTER FOR OGIVE RADIUS (INCHES):
BULLET LENGTH (INCHES):1.150 AHEAD OF BASE: .378
BOATTAIL LENGTH (INCHES): .185 BELOW AXIS: -2.310
BOATTAIL LENGTH (% OF CAL):0.60 APPROX CENTER OF GRAVITY (INCHES):
BOATTATL END DIA. (INCHES): .270 AHEAD OF BASE: 0.491
BOATTAIL ANGLE (DEGREES): 5.9 SECTIONAL DENSITY: .233
BEARING LENGTH (INCHES): .193 BALLISTIC COEFFICIENT AT STD METRO SL:
BEARING LENGTH (% OF CAL):0.63 C1= .472 C7= .235 AT 2970 FPS
OGIVE LENGTH (INCHES): 0.772 WEIGHT (GRAINS): 155
OGIVE LENGTH (% OF CAL):2.506 OGIVE RADIUS (INCHES): 2.464
OGIVE TYPE: TANGENT TWIST RATE FOR STABILITY FACTOR OF 1.5:
MEPLAT DIAMETER (INCHES):.055 13.5 (INCHES/TURN)
AT 2970 FPS MUZZLE AND STD METRO SLAPPROX WIND DRIFT PER 10 MPH (INCHES):
100 YDS 0.6 200 YDS 2.6 300 YDS 6.1
Comment: The BJD has a much better Coefficient of Drag so has better retained velocity past 600
[/b]
Cheers
Peter Hulett
BJD 155gn 30 Cal
Calculations by K. Sellick
Based on actual measurement.
For comparison only - not
guaranteed to be accurate.
Both projectiles were run
through the same ballistic
modelling program
BULLET DESIGN PROFILE FOR: BJD 155gn 30cal
DATA FOR PHYSICAL MEASURMENTS, WEIGHT, SECTIONAL DENSITY, CENTER OF GRAVITY,
BALLISTIC COEFFICIENT, AND GYROSCOPIC STABILITY
LEAD CORE, JACKETED HP OGIVE RADIUS (CALIBERS):12.0
BULLET DIAMETER (INCHES): .308 CENTER FOR OGIVE RADIUS (INCHES):
BULLET LENGTH (INCHES):1.125 AHEAD OF BASE: .018
BOATTAIL LENGTH (INCHES): .175 BELOW AXIS: -3.504
BOATTAIL LENGTH (% OF CAL):0.57 APPROX CENTER OF GRAVITY (INCHES):
BOATTATL END DIA. (INCHES): .270 AHEAD OF BASE: 0.444
BOATTAIL ANGLE (DEGREES): 6.2 SECTIONAL DENSITY: .233
BEARING LENGTH (INCHES): .370 BALLISTIC COEFFICIENT AT STD METRO SL:
BEARING LENGTH (% OF CAL):1.20 C1= .458 C7= .228 AT 2970 FPS
OGIVE LENGTH (INCHES): 0.580 WEIGHT (GRAINS): 154.8
OGIVE LENGTH (% OF CAL):1.883 OGIVE RADIUS (INCHES): 3.696
OGIVE TYPE: SECANT TWIST RATE FOR STABILITY FACTOR OF 1.5:
MEPLAT DIAMETER (INCHES):.045 13.0 (INCHES/TURN
AT 2970 FPS MUZZLE AND STD METRO SL APPROX WIND DRIFT PER 10 MPH (INCHES):
100 YDS 0.6 200 YDS 2.7 300 YDS 6.2
BULLET DESIGN PROFILE FOR: Sierra 155gn Matchking
DATA FOR PHYSICAL MEASURMENTS, WEIGHT, SECTIONAL DENSITY, CENTER OF GRAVITY,
BALLISTIC COEFFICIENT, AND GYROSCOPIC STABILITY
LEAD CORE, JACKETED HP OGIVE RADIUS (CALIBERS): 8.0
BULLET DIAMETER (INCHES): .308 CENTER FOR OGIVE RADIUS (INCHES):
BULLET LENGTH (INCHES):1.150 AHEAD OF BASE: .378
BOATTAIL LENGTH (INCHES): .185 BELOW AXIS: -2.310
BOATTAIL LENGTH (% OF CAL):0.60 APPROX CENTER OF GRAVITY (INCHES):
BOATTATL END DIA. (INCHES): .270 AHEAD OF BASE: 0.491
BOATTAIL ANGLE (DEGREES): 5.9 SECTIONAL DENSITY: .233
BEARING LENGTH (INCHES): .193 BALLISTIC COEFFICIENT AT STD METRO SL:
BEARING LENGTH (% OF CAL):0.63 C1= .472 C7= .235 AT 2970 FPS
OGIVE LENGTH (INCHES): 0.772 WEIGHT (GRAINS): 155
OGIVE LENGTH (% OF CAL):2.506 OGIVE RADIUS (INCHES): 2.464
OGIVE TYPE: TANGENT TWIST RATE FOR STABILITY FACTOR OF 1.5:
MEPLAT DIAMETER (INCHES):.055 13.5 (INCHES/TURN)
AT 2970 FPS MUZZLE AND STD METRO SLAPPROX WIND DRIFT PER 10 MPH (INCHES):
100 YDS 0.6 200 YDS 2.6 300 YDS 6.1
Comment: The BJD has a much better Coefficient of Drag so has better retained velocity past 600
[/b]
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Peter Hulett
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stu_bear2002
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pjifl
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Peter Hulett gave particulars of the BJD and Sierra projectiles we use based on measurements made by K. Sellick.
The BJD was taken to have an ogive radius of 12 cals.
In a document prepared fot the NRAA, Dyer specifies 10 Cals for the current BJD projectile.
I have measured it at about 9.5 cals.
Of course some error is present in these measurements, and the projectile shape out of a die may differ slightly from the die itself, but I would suggest that the figure of 12 is definitely in error.
The SMK 155 is also mentioned as having an Ogive radius of 8. My measurements give about 7.7 which is in reasonable agreement.
Peter Smith.
The BJD was taken to have an ogive radius of 12 cals.
In a document prepared fot the NRAA, Dyer specifies 10 Cals for the current BJD projectile.
I have measured it at about 9.5 cals.
Of course some error is present in these measurements, and the projectile shape out of a die may differ slightly from the die itself, but I would suggest that the figure of 12 is definitely in error.
The SMK 155 is also mentioned as having an Ogive radius of 8. My measurements give about 7.7 which is in reasonable agreement.
Peter Smith.
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pjifl
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I just had a look at the NRANZ website.
There is something else wrong.
They say the BJD projectile has a better coefficient of drag so has better retained velocity.
But if you look at the figures given for BC and wind effect one would assume the opposite.
I would NOT be taking these figures for granted at all.
Peter Smith.
There is something else wrong.
They say the BJD projectile has a better coefficient of drag so has better retained velocity.
But if you look at the figures given for BC and wind effect one would assume the opposite.
I would NOT be taking these figures for granted at all.
Peter Smith.
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