The maximum in Hodgens reloading is 8.7grains.
BULLET WEIGHT
180 GR. SIE JHC
Starting Loads Maximum Loads
Manufacturer   Powder   Bullet Diam.   
C.O.L.
Grs.   
Vel. (ft/s)
Pressure
Grs.
Vel. (ft/s)
Pressure
Hodgdon   800-X   .400"   1.260"                  8.7   1,210   30,000 PSI

9.3 is quite a bit over.

If I want more I'll grab my 44mag or rifle.

I use New Starline and resize them and every other piece of brass I shoot.

I shoot a lot of 175 gr LEE swc. They usually weigh about 180grains. I use a fast pistol powder, in my case Promo and build up the load till it cycles  my G20 reliably Then add .2 grains more. Yes I have the full power loads but would rather enjoy the accuracy and light recoil of my homebrew load.

I would be cautious about using the technique with FMJ.

As with all hand loading you are on your own if you get a double charge or other issues. I set all my primers one at a time in a hand press and only do the charging and bullet seating in my progressive press.

I know it is an old topic, my first post here. The Bond is known to have chambered their derringer in 44mag. Mine is strictly 45 colt, 650fps with a factory type load. Makes a huge fireball with 230 grain ACP bullet and a goodly amount of unique.  The lower barrel is pretty much regulated to the sights.