Hello Horde, sorry of the long delay. I finally got to the range to shoot the Cavity Back bullets into gels - that I loaded up in October.
The 118 gr Cavity Back MKZ bullet measures 1.349" long and has a G1 coefficient listed at 0.530. The cavity is 0160" deep and holds about 0.8 gr CFE223.
I weighed 10 as I pulled them from the box and they varied between 117.1 to 117.7 gr with an average of 117.3 with 4 of them weighing 117.2 None weighted 118 gr.
Using the methods published in Chapter 6 - Terminal Ballistics in Vol 2 of the 6.5 Grendel Reloading Handbook here's what I got:
Starting from Left:
1789 fps, 23.5" penetration, 117.4 gr, expanded to 0.510"
2165 fps, 25.0" penetration, 117.4 gr, expanded to 0.625"
2433 fps, 22.0" penetration, 106.5 gr, expanded to 0.630"
One petal on the third shot had broken off. The other two retained essentially 100% of their weight.
At 2433 fps, the bullet entered the gel at left and opened up after 1⅜" penetration, then "propellered" through the gel. The fragments shown are from previous tests (NOT the CBB) and are sitting on top of the gel
The permanent cavity is about 1.10" diameter for 5" then narrows to about 0.5-0.6".
My findings agree well with those published by CBB: http://www.cavitybackbullets.com/category-s/114.htm
This bullet opened up below 1800 fps, likely to be down in the high 1600s/low 1700s. Which is MUCH lower than the Barnes.
Really exciting new bullet for the Grendel. I've got the 105 gr CBBs loaded up for next test. The 105 is only 1.246" long which may be better suited for mag length loading.
See PredatorDown's range report on the 118gr..
The 118 gr Cavity Back MKZ bullet measures 1.349" long and has a G1 coefficient listed at 0.530. The cavity is 0160" deep and holds about 0.8 gr CFE223.
I weighed 10 as I pulled them from the box and they varied between 117.1 to 117.7 gr with an average of 117.3 with 4 of them weighing 117.2 None weighted 118 gr.
Using the methods published in Chapter 6 - Terminal Ballistics in Vol 2 of the 6.5 Grendel Reloading Handbook here's what I got:
Starting from Left:
1789 fps, 23.5" penetration, 117.4 gr, expanded to 0.510"
2165 fps, 25.0" penetration, 117.4 gr, expanded to 0.625"
2433 fps, 22.0" penetration, 106.5 gr, expanded to 0.630"
One petal on the third shot had broken off. The other two retained essentially 100% of their weight.
At 2433 fps, the bullet entered the gel at left and opened up after 1⅜" penetration, then "propellered" through the gel. The fragments shown are from previous tests (NOT the CBB) and are sitting on top of the gel
The permanent cavity is about 1.10" diameter for 5" then narrows to about 0.5-0.6".
My findings agree well with those published by CBB: http://www.cavitybackbullets.com/category-s/114.htm
This bullet opened up below 1800 fps, likely to be down in the high 1600s/low 1700s. Which is MUCH lower than the Barnes.
Really exciting new bullet for the Grendel. I've got the 105 gr CBBs loaded up for next test. The 105 is only 1.246" long which may be better suited for mag length loading.
See PredatorDown's range report on the 118gr..
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