Thanks fellas,
My arrows are Goldtip Traditional in the old 75/95 cut to 31 inches. I wanted to go heaviest % FoC so went with a 100gn insert and started with a 300gn head for the bareshaft tune and it flew straight. I also confirmed it with paper tuning.
This gave me a 770gn arrow at just under 25% FoC. I also run 4x4 inch feathers on my arrows.
As for the broadheads, I ordered some VPA's and 200gn Grizzly with 100gn inserts and was waiting on these to arrive when I went hunting. The original plan for this trip was to hunt pigs, so I borrowed some Aussie made Kayuga broadheads (130gn) from my mate and thought the arrows will be a bit stiff but at 600gn, they would handle pigs at close range easy enough.
As it turned out, they did the job on buffalo just fine. The first arrow managed to reach both lungs, as we came across the bulls bloodtrail on the way out and it was a constant stream the whole way. I never got to confirm penetration depth as he rolled onto that arrow when he died.
The second arrow went through a rib, and I guess got around half penetration. The final arrow slipped in between ribs and only had the nock showing.
I draw around 29 inches, so I'm guessing it's about #68 at my draw length.
Cheers,
Memo.