I cast up some of these "cruise missiles" this morning (just got the Midsouth package yesterday) - they dropped .270 and around 175gn WW. I hand fit gas checks, and pan lubed in NRA formula.
I loaded them over 15 grain of 2400, and went to the range with a Vetterli, which is gain twist like the M91's.
The results I could almost call a group, but all the bullets went through sideways. Clearly a stability problem.
Anyone have wisdom or suggestions on this?