Use .301” bullets. It is worth acquiring a die to size down .308/.312” ready cast bullets of 80 to 90 grains made for .32 S&W or .32 ACP.

As to “a few years” ago Kynoch pulled the plug on all centre-fire rounds in 1972. I doubt if they had actually made a batch in this calibre since the early 1960’s.

If you can find any factory rounds in boxes marked Non-Rusting or Non Corrosive they take the No. 69 Berdan primer.

I have found that Pre-1939 cases take a slightly larger primer so No. 69 primers look as if they should fit but then fall out.

Bertram make Boxer primed cases.