Looking for loading data for the 505 Gibbs using a 600 grain bullet. Powder preferences etc.
You'd be better off posting in the express rifles forum or the gunwriters forum. This forum doesn't get much traffic.
Might want to peruse this thread
https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/10699939/505_Gibbs_modern_powders.or get a copy of Handloader 277 or August 1999.