If the loads are listed "For Ruger and Contender Only" I'd follow that guideline for pressure.
Standard loads will show higher velocity from the longer barrel but (my understanding is) the chamber pressure will be acceptable.
If they feed in your rifle, as Ed has pointed out!


"Camping places fix themselves in your mind as if you had spent long periods of your life in them.
You will remember a curve of your wagon track in the grass of the plain like the features of a friend."
Isak Dinesen