I concur, Johan is right about the string jumping ability of piggies and impalas. The kudu I shot was fine but I needed over 600 grains for some more penetration and I have already set up 600 plus arrows for the trip back this July to SFA. But them darn warthogs and impala. These are not thick animals, no big bones, just like piggies and deer that I shoot all the time in the states except for their unique ability to jump, duck and laugh at you. Both my warthog and impala ducked over 6 inches resulting in high shots at less than 15 yards. The arrows on both the pig and impala took out both lungs but no pas through do to wieght and the animals twisting and jumping upon imact. I did recover both and the video clearly showed the arrow striking the exact spot where I aimed on the pig, except for the fact that the pig refused to stay still. My bow, I thought, was quiet and I have taken 2nd shots with the same bow on the same animals before. Obviously the setup wasn't quiet enough for those two. You can clearly see the warthog start to move away before the arrow left the bow. I thought it was calm and watched it and the other piggies for several minutes while they ate and watered but it must have known something was up. The one thing I took from that trip was a new found respect for the warthog and impala as a bowhunting troghy. I still love my kudu but ... it seems easy compared to hunting the string jumpers.