Thank you Joel, I was hoping you would offer your experience with 300gr bullets. I've only shot paper with mine, so have no on game performance experience, but I knew that you had problems with close range performance with loads that would work at 200yds.
My only recommendation is for better bullets for the long work that will also work on the close stuff without blowing up. The Rem 300gr doesn't fit that catagory from all reports at MO. One bullet that has an exellent reputation and still shoots "flat" if the .45-70 can be considered in that context, is the 300gr Nosler Protected Point Partition. It's operating velocity for terminal performance is 800fps to 2400fps+ according to Nosler. But as Joel mentioned, the recoil is viscious.
I think a better option with more tolerable recoil would be a 350gr bullet at around 2000fps, recoil is tolerable, yet it will still reach out to 200yds with no hold over. I haven't shot anything at 200yds except the PMC +P ammo which has since been discontinued. Sighted in 4" high at 100yds, it was 6" low at 200yds, which would be good for deer or elk as it had right at 1500lbs energy at 200yds from PMC's data. I never chrono'd it, but their trajectory info was right on.
Tim