Alright guys... I havent loaded 45/70 in about 10 years so maybe I am forgetting something. But, I killed 4 cases this morning by kinking the cases while seating the bullet. I sized and belled and then bent. Kinda frustrating. Any ideas?

Either go to a separate seating and crimping or just back off on the crimp just a hair. I'd bet you are crimping too hard and crushing the case.
Joe

The logical setup procedure for setting the seat / crimp die is as follows:

Back the die out of the press until there is no crimp whatsoever when a cartridge is raised into the die

Adjust the seating stem (down) into the die until the desired seating depth is achieved. Back the seating stem all the way up in the die body

Raise the case with properly seated bullet all the way up into the die, then lower the die body until you feel resistance. Lower the die more (bit by bit, checking after each adjustment) until the desired crimp is achieved. You should only just be able to see the case mouth crimping.

With the cartridge still all the way up in the die, lower the seating stem until it connects the bullet firmly.

Your die should now be set up correctly.

Check your brass length; the brass may have stretched. Then readjust your dies as previously stated. also check for build-up of bullet lube in the die (assuming that your using lead bullets). this will cause this problem also.
Mike