YeeHaa! That'll do!
I used to have the same opinion of Starline brass because of my handgun brass experiences. Then, I bought 200 pieces of Starline .45-70 brass to go with my new Shiloh because I couldn't find any Remington or Winchester, much less Jamison.
My Starline brass isn't too hard. It seals the chamber quite nicely, I get consistent bullet pull, and it is very consistent in weight and other dimensions.
Ed