Thanks for all the comments.
I didn't tell you the length of the barrel, my mistake. It is a Super 14 pruned to 12 inches.
I used the high priced bullets in the Marlin initially because I thought I needed the extra punch of the partition bullet. They group much better at 100 yards with my Marlin (less than an inch for a 5 shot group vs four inch groups. But where I hunt I never get a shot longer than about 40 yards anyway. So my guess is that you are right, it is a waste of money.
Well, maybe I can get a scope on the barrel this weekend and see if I can hit anything with it,
Again, thanks for all your help folks. This is a good campfire to sit around!