Some further subsonic experimenting

The last loads I reported on caused this reaction from one of the knowledgeable people I know:
"What?  This was a semi-auto?  And it CYCLED with those velocities?"

A lot of thinking, reading, and digging around followed, and today I tried two loads: one using A5744 propellant, and one using 2400.

DISCLAIMER:
There is no published handloading data for this bullet and cartridge, so I'm going by estimates, what some people have written about, and guesswork.  This- so far- has worked for me, which does not mean it'll work for you in your rifle.  If you give this a try, it's all on you.

The first target was two rounds of Hornady factory Sub-X ammo to set elevation.  Second was five rounds with 10.5 grains of A5744.  One round at a time, checking primers and for anything else that looked like a bit high pressure, and all looked like a standard fired primer.

Number 3 target was one round using 9.5 grains of Alliant 2400.  Only one because that primer was pretty flattened, which is not good.  So I'll pull the bullets from the other four, mark this load in the 'Nope' column, and move on.  This one had the same elevation as the factory stuff, but I'm not chancing it again.  I'd hoped for this one to be good because 2400 is a ball powder that flows very nicely through a powder measure.

So I'll try some more 5744, adding a tenth of a grain to several sets to check for pressure signs, and hopefully running them over the chronograph