221028HV139 Technical Profile ©   Application: General Hunting
Barrel Bore Diameter: 0.218" 5.530 mm The diameter of the barrel from land to land.
Barrel Groove Diameter: 0.221" 5.620 mm The diameter of the barrel from groove to groove.
Bullet Weight: 28gr 1.8g Bullets are guaranteed to weigh within 0.25% of the stated weight.
Bullet Length: 0.50" 12.750 mm
Secant Ogive Length: 0.27" 6.732 mm These dimensions are critical to consistent external ballistic performance and are held constant to within 0.005 mm (0.0002")
Meplat Diameter: 0.09" 2.200 mm
Min Bullet Protrusion: 0.31" 7.830 mm Add the case length to these numbers to determine the maximum and minimum cartridge overall length that is possible with this bullet.
Max Bullet Protrusion: 0.39" 10.000 mm
Bullet conforms to CIP and SAAMI for magazine length. Check the magazine length of your rifle for suitability with this bullet.
Maximum M/V: 4700fps 1 433 m/s If the maximum muzzle speed is exceeded, dynamic stabilty problems may be encountered.
Short Range Twist: 11.5" / 293 mm or tighter 53.0 Cal/length or tighter Twist recommended if maximum hunting distances are 120 yards or 110 m. A tighter twist (smaller number) can be used.
Twist: Sg = 1.5: 14.0" / 353 mm 63.9 Cal. in length General hunting twist for average distances to 250 yards or 230 m.  A tighter twist (smaller number) can be used.
Minimum Twist: 15.5" / 393.7 mm 71.2 Calibers in length The twist required for stable flight and good terminal performance further than 250 yds or 230 m. See the 'Notes' hereunder.
Minimum Impact Speed: 1600fps to 1700fps 488 m/s to 518 m/s At this impact speed, the bullet will open to at least double caliber.

Calculated Ballistic Coefficient - G1 profile
BC = -0.000      For exact values, shoot drop tables at the elevation and temperature for your location.
BC = -0.000    
BC = -0.000    

Suitable Cartridges, with consideration of the above specifications:

5.7x28

NOTES
A Gyroscopic Stability (Sg) greater than 1.1 is required for stable flight with HV and HP bullets. For hunting under 250yds/230m, an Sg of up to 1.5 or more can be used. For longer distances the Sg can be decreased but never less than 1.1.
*Note that Sg increases as twist tightens.  *A 1:10" twist is tighter than a 1:12" twist within a given caliber only. *Twist rates given in caliber lengths can be compared across calibers. *Choose a bullet length best suited to your rifle twist and type of shooting.  *When a bullet is specified for a given twist rate, it can also be used in any twist that is tighter.  Using it in a slower twist than specified, is not advisable. *Some experimentation will be required to determine exact drop tables for your equipment and location.