when using fast expanding bullets you simply must keep to the softer targets, ie the rib cage and you will love the effects... remember you will get rapid expansion and thus reduced penetration... so don't punch through heavy bone on th eway to the vitals; no going away shots to break down and penetrate through, the shot I would dread with it is quartering onward on a large buck, aiming at the spot to the front of the shoulder could prove a problem.. but I have used those and some 180s too and had no problems, but was extemely careful about shot placement and was really pleased... the penetration was not bad on riv cage shots, that is.. ... I just played it safe.
Remember, shot placement is all, anyway... I would use other bullets if I could, just for a margin of error and so that I do not have to pass on frontal shots that I otherwise could take easily, etc.
I used the lighter stuff when I had reloaded a ton of them and then brought only that for some hunts and then did not want to sight in again with my 44 auto I used at the time.
good luck with your choice and i hope you do not use them and regret it.. that is why it is always a struggle : do what you wnt veruss be as safe as I choose to be.. lol.
dk