OK, gurus, what gives? I am using brand new 45-70 brass (Remington brand) and Sierra .458 dia 300gr FN HP bullets. I have resized the brass and even tried it just as it comes out of the bag. The round on the left is the result. If I ream the inside of the case heavily to where it is almost a V, I get mixed success, but still get a lot of rounds that look like the 4 on the right. Is there some way to shape the neck of the case so it has a slight bell or what do I need to do? I have reloaded a lot of stuff, but this is my first attempt at these straight-walled 45-70's and I am obviously missing something. HELP!