Just picked up a MINT Swede M38 bent-bolt Mauser short rifle, looking like it was just issued from the armory; only 1 tiny ding on it that should ‘iron’ or steam out.
Slugged the bore @ 0.267”, but only had some “cruise missile” clone powdah-coated 170-grain cast from Gardners Cache, also @ 267. The 170s are over anything in weight I can find in books, so I tried the ubiquitous ‘The Load’ of 16-grains of Alliant 2400, but they tumbled @ 50-yards & shot a 3’ group or bigger …
Now I hear that 6.5s can be TOUCHY to load for cast loads, and the Swede has a fast 1-in-9” twist … but heavier bullets like fast twists. My fear is I didn’t push them fast enough … but w/no published load data to go by … well, I’m out of ideas. Thoughts?