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Finally got test the Cavity Back Bullet 105 gr today.
The 105 is much shorter than the 118 at 1.246" iong. It has a single groove versus two for the 118.
The G1 is listed to be 0.480.
CBB also recommends 1700 - 3000 fps. That's 100 fps higher than the 118.
Based on my experience with the 118, I weighed 10 of the 105s and measured 105.4 to 105.9, with seven of them being either 105.8 or 105.9.
Using the methods published in Chapter 6 - Terminal Ballistics in Vol 2 of the 6.5 Grendel Reloading Handbook here's what I got:
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Left: 2088 fps, expanded to 0.435", penetration >17" (hit bottom of second gel
Right: 1724 fps, no expansion, penetration was >25" as it took a curved path.
As CavityBackBullets pointed out in post #9 on the related thread, the 105s are made to a higher hardness than the 118s. http://www.65grendel.com/forum/showt...gr-gel-results
This data supports the higher hardness. The 105 did not open at all at 1724 fps. The tip was damaged when it struck the bottom metal plate.
The gel below shows the 1724 fps shot at the top, leaving very little of a cavity until it flipped over after 13". The second track was at 2113; third was 2247, forth was 2088; and the 5th was a commercial SST traveling at 2511 fps. You can see the red tip in the second node of the track. Only the two shown were recovered. All others exited the top of the second get.
The stars were aligned just right today as the 1724 fps shot hit the bottom metal plate and bounded up and took a right turn going base first. It spent its energy as it reached the edge of the gel. About half of the bullet protruded through the side. In baseball, we'd call that a "snow cone". Sometimes, you get lucky.
The 105 is much shorter than the 118 at 1.246" iong. It has a single groove versus two for the 118.
The G1 is listed to be 0.480.
CBB also recommends 1700 - 3000 fps. That's 100 fps higher than the 118.
Based on my experience with the 118, I weighed 10 of the 105s and measured 105.4 to 105.9, with seven of them being either 105.8 or 105.9.
Using the methods published in Chapter 6 - Terminal Ballistics in Vol 2 of the 6.5 Grendel Reloading Handbook here's what I got:
https://
Left: 2088 fps, expanded to 0.435", penetration >17" (hit bottom of second gel
Right: 1724 fps, no expansion, penetration was >25" as it took a curved path.
As CavityBackBullets pointed out in post #9 on the related thread, the 105s are made to a higher hardness than the 118s. http://www.65grendel.com/forum/showt...gr-gel-results
This data supports the higher hardness. The 105 did not open at all at 1724 fps. The tip was damaged when it struck the bottom metal plate.
The gel below shows the 1724 fps shot at the top, leaving very little of a cavity until it flipped over after 13". The second track was at 2113; third was 2247, forth was 2088; and the 5th was a commercial SST traveling at 2511 fps. You can see the red tip in the second node of the track. Only the two shown were recovered. All others exited the top of the second get.
The stars were aligned just right today as the 1724 fps shot hit the bottom metal plate and bounded up and took a right turn going base first. It spent its energy as it reached the edge of the gel. About half of the bullet protruded through the side. In baseball, we'd call that a "snow cone". Sometimes, you get lucky.
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