Not with 180s but with 200s. I would suspect that the 180s would work well. Next time out I would take the RS and the P along and Start at 65 or 70 grs.
Remember the 45-70 killed lots of buffs with 70 grs of BP and a 405 gr bullet just poking along at a moderate speed.

I've shot deer with the 200 grainers too, but not the 180's. I would agree with bronko that the 180 grainers would work just fine for deer - though with the 180's I doubt that you would get pass-thru's very often.

Van - I am truly sorry about you less than satisfactory results based on my recommendation but I dug up that target and like I thought, the 70 gr load was a bit more accurate but I had to juice it up to 80 gr so I could have a lower POI. My rear sight was as low as it could get.
Here is the target

Is that a 3" dot on that target bronko? I would be REAL happy with that group.

I believe that dot is about 3". And of course like you said earlier, that was with the open sights. I was happy with it too. I've also found that the Pyro P works great in my Genesis 50 cal with 300 gr .430" XTPs and a 100 gr charge and also in my new .45 cal 15/16" barrel I got for the Hawken.
I've tried FFg, FFFg, T7, Pyro RS, but in these 3 rifles, the P works the best. The Pyro RS works well in my 50 cal percussion LRH barrel. About the only thing that the T7 worked well with was my 54 cal Renegade barrel which I sold.