Balistix RBT Ultra Hunt (BC & Twist Rate)

View the Notes below the table.

Balistix RBT Ultra Hunt BC & Twist Rate

CalibreBullet WeightBullet TypeG1 BCG7 BCBarrel Twist
Rate (Typical)
Stability Factor (SG)
Sea Level @20DegC
Stability Factor (SG)
Highveld (1400m)
@ 20DegC
.308"155grRBT Ultra Hunt0.310.15121.571.85
.308"165grRBT Ultra Hunt0.340.17111.772.07
.308"175grRBT Ultra Hunt0.350.17101.992.36
.323" / 8mm200grRBT Ultra Hunt0.450.22101.982.34
.338"250grRBT Ultra Hunt0.420.21101.912.26
.365" / 9.3mm230grRBT Ultra Hunt0.310.15141.942.3
.375"250grRBT Ultra Hunt0.330.16122.072.45


Version: 2019-07-10
Note: Bullet geometry obtainable from Balistix Quick Load bullet file.

Balistix “Ultra Hunt” Bullet:
The Ultra Hunt bullet design is derived from the HunTac bullet and provides an extra feature on the bullet tip that allows for rapid expansion. This rapid expansion will result in deadly terminal efficiency. Ultra Hunt bullets share the same ogive design for supreme accuracy but will have a reduced BC and therefore are not ideal for long range hunting. Typical application of these bullets are bush hunting.
G1 BC:
Mathematically calculated at Mach 2.5. G1 BC is derived from a flat base design model and should not be used for long range ballistic trajectory calculations. G1 BC is however sufficient for short range (up to 300m) shooting.
G7 BC:
Mathematically calculated at Mach 2.5. G7 BC should preferably be used for a boat tail bullet design therefore more applicable to Balistix bullets.
Actual BC:
Please note that actual BC is drastically influenced by muzzle velocity and atmospheric conditions. Please follow the procedure on our website in order to determine the exact BC for your rifle. (
A Rebated Boat Tail bullet combines flat base bullet accuracy properties with boat tail BC enhancements. International studies have shown that a Rebated Boat Tail design can yield an increase in accuracy of up to 15% compared to conventional boat tail designs.
SG (Gyroscopic Stability Factor):
SG < 1.0 = unstable and should not be used.
SG 1.0 to 1,5 = marginally stable*. This is a “grey zone” and tests with your rifle and bullet combination will reveal a stability problem or not.
SG > 1,5 = perfectly stabilised.
* Please note that marginally stable does not mean the bullet will not shoot well. If your bullet holes are perfectly round/symmetrical on a paper target it implies that the bullet is stabilised in your rifle. If you note any form of “key holing” on your target, at any distance, then your rifle and or environmental shooting conditions are not suitable for our bullet.
Balistix Information File Version:
Information and product may change without notice. Please check web page regularly for latest revision. Revision date is underneath information table.