You got an awesome deal. I own a Marlin Guide Gun in 45-70 and it is a shooter. Very pleasant to shoot with 300 grain bullets. Those Hammerheads are incredible. If you shoot one, you might hesitate to shoot a second one. That round is used for the largest and most dangerous animals in Africa and Garrett knows what he is doing. I would like to hear a range report on your experience with them. Congratulations on the excellent find. Enjoy.