uno676 We have the same conical rule here in Idaho although ours is a little more restrictive, we have to use a lead conical.
I think you might have a couple options... One, being the Hornady FPB and Two, the Thors all copper bullet. With the Thor you will have to find the one that fits your bore best. The FPB's will need to be started with a good rap on a short starter and the npushed home with the ram rod.
Another option and the one I use during a ML is a .503-460 grain Bull Shop lead conical... This is an absolute elk stopper...
Problem being that not all TC guns will shoot a lead conical because of a mis-aligned QLA. My Triumph and Omega both do shoot them very well but others do not.
It would be my suggestion to try the FPB's as they are less expensive, either the 300 grain or the 350, especially if you are going after elk. It has been reported that the 350's are more accurate, but I have no way of proving that as I have not shot them....
Now the outside possibilty.... Lehigh Bullets will possibly be making a sabotless bullet this summer that would be a great answer for you. I am shooting some now and they are extremely accurate.
This is the test bullet, and I think Dave will work them into production this summer. They are 50 cal - 270 grain.
Here is one of my shooting trips with this bullet...