I use RCBS 7.62x54R dies and yes they come with both .308 and .310 expander balls. For brass I’ve been having great luck with fired cases from Winchester White Box 180gr SPs. I recently bought a Finnish M39 and decided to load up some 7.62x53R with .308 Hornady 150gr bullets to see how they’ll shoot compared to the same style Hornady .311 bullets. Using the .308 expander the neck tension seams adequate to hold the smaller bullets correctly. I have yet to shoot the M39 so I’ll post an update after I get to the range. So far IMR4350 and Hodgdon (sp) VARGET have worked out very well and I have had not issues using Standard Winchester Large Rifle Primers (pierced or light firing pin strikes) with any of my Mosin Nagants as long as the firing pin is adjusted correctly. I’m having great fun studying the history and experimenting with loads for my M44, 91/59, and now M39. Unfortunate, space is getting tight in the gun safe and I’ll probably sell my Laminated M44 at the next gun show.
