Dave, the factory says the NEF/H&R is rated for lever-gun pressures, not Ruger levels. A lot of guys push the limit but all they are doing is damaging the rifle.
Stick to the 2.4 or 2.6 and get great performance at reasonable pressure.

P.S. Track of the Wolf has 2.6 and 2.4 cases for about 80 to 87 cents each.

http://trackofthewolf.com/(S(v1vjvze0ar3...e=10&Page=5