I was looking at the 300gr and 350gr Barnes X bullets for use in my Encore 45/70. They seem like they would make a dandy moose bullet. I just wondered if they would expand at 45/70 velosities. Striking velosities of 1700-1500fps. Any practicle experience would be appreciated.

e-mail barnes to get their input, but I believe 1800 fps is the low end on velocity, and I'd personally want them to be hitting around 2000 fps or more.

As an asside, a friend shot a grizzly with a 400 gr A-frame out of his contender @~1700 fps, and it apparently didn't expand.

You might be best off with the Remington 400 gr, which is designed for the lower 45-70 velocities.