Alright, work day complete and so is a little shop fun time, dummy rounds made.
140gr RDF's at 3.070 coal 147gr ELD's at 3.105 coal 150gr SMK's at 3.120 coal
Best I can do here at the farm with a caliper says the RDF has the shortest base to ogive length by a rch at .740, 147 horn went .744, 150gr SMK went .770.
I'll be looking for 29-3000 fps with whichever bullet is most accurate, 28 inches of barrel and Retumbo should get it there, BR2's to get it lit, this is going to be a fun project, package will leave for 'Smiths tomorrow.