I just recently acquired an older model 1894 in 44 Mag. It's the old round barrel model with microgroove rifling. I generally shoot hard cast in all my 44's, both rifle and revolver, but I understand that these older models don't do well with cast. Would a barrel change be prohibitive? I got this rifle for free from a relative, so I feel an investment of $300-$400 wouldn't be too much.