cohunt
Well-Known Member
Here is my personal experience and opinion on the cbb.
I tried the 168 in a 308 gas gun and wasn't happy with speed or accuracy, he also had a 165 non tipped version a while back and I had similar results.
I do shoot his 195 mkz subs in my 8.5" 300bo pistol but I had to try 4 powders and change coal to find a good load but I'm happy with those for my purposes. ( they supposedly expand down to 600fps)
As far as the "cavity back" goes--- I wish he would change his wording.....I'll explain: Robert's bullet nose design isn't anything different, that means that it's the rear of the bullet that is modified (hence the cavity)---- but copper has a certain density (physics won't allow changes in that)---- if you keep it the same weight but put a hole in the base, then you have to extend the "tail " to retain the weight--- so a 168gr cavity back would still take up the same case capacity as a 168 non cavity back as long as the nose design and coal don't change---- so you can't fit any extra powder in the case no matter what the base looks like, it still takes up the same volume. I don't think the cbb are lathe turned iirc.
I feel he should have said the cavity lightens the bullet slightly over a non cavity design thus allowing slightly more case capacity.....so his 168 design allows more capacity than an identical 175 non cavity design (with the same nose profile and coal)
The cavity MAY act similar to a rebated boat tail though in regards to how the gasses react to its design but I havent seen any proof of this anywhere I can find.
If you use his bullets, I recommend using like weight reload data for barnes bullets as I could never push his bullets as fast as like weight lead core bullets (in my limited trials)
I'm pretty sure Zen A has used his 6.5 bullets in his Grendel, maybe he will chime in too with more actual first hand knowledge ( on 68f - " Texas lawman" has used them too, he had some vids of his results too)
I would love to see side by side of hammer and cbb---- but the hammer uses a pedals off design, and the cbb uses an expanding pedal design so they have different designs in regards to expansion and wound trauma....it would be cool to see side by side gel block tests and max speed tests to draw our own conclusions
I tried the 168 in a 308 gas gun and wasn't happy with speed or accuracy, he also had a 165 non tipped version a while back and I had similar results.
I do shoot his 195 mkz subs in my 8.5" 300bo pistol but I had to try 4 powders and change coal to find a good load but I'm happy with those for my purposes. ( they supposedly expand down to 600fps)
As far as the "cavity back" goes--- I wish he would change his wording.....I'll explain: Robert's bullet nose design isn't anything different, that means that it's the rear of the bullet that is modified (hence the cavity)---- but copper has a certain density (physics won't allow changes in that)---- if you keep it the same weight but put a hole in the base, then you have to extend the "tail " to retain the weight--- so a 168gr cavity back would still take up the same case capacity as a 168 non cavity back as long as the nose design and coal don't change---- so you can't fit any extra powder in the case no matter what the base looks like, it still takes up the same volume. I don't think the cbb are lathe turned iirc.
I feel he should have said the cavity lightens the bullet slightly over a non cavity design thus allowing slightly more case capacity.....so his 168 design allows more capacity than an identical 175 non cavity design (with the same nose profile and coal)
The cavity MAY act similar to a rebated boat tail though in regards to how the gasses react to its design but I havent seen any proof of this anywhere I can find.
If you use his bullets, I recommend using like weight reload data for barnes bullets as I could never push his bullets as fast as like weight lead core bullets (in my limited trials)
I'm pretty sure Zen A has used his 6.5 bullets in his Grendel, maybe he will chime in too with more actual first hand knowledge ( on 68f - " Texas lawman" has used them too, he had some vids of his results too)
I would love to see side by side of hammer and cbb---- but the hammer uses a pedals off design, and the cbb uses an expanding pedal design so they have different designs in regards to expansion and wound trauma....it would be cool to see side by side gel block tests and max speed tests to draw our own conclusions
