About the max long range performance you're going to get is from one of the wildcats long the lines of .309 JDJ (SSK Industries), .30 BRM (EA Brown), .308 B e l l m, etc. You're going to gain a decent amount of velocity over the .30-30, but if you want significantly more then you will have to go over to the Encore platform. There's no reason to push a Contender beyond its limits and risk life and limb when there are better tools for the job.