My best Breech seated loads are 1.5 - 1.6 gr of B'eye. It's subsonic, in my rifles. I don't use wads because you can hold the case parallel, even slightly down w/o any powder spilling. I have let my wife use a flora foam wad, until she got use to loading but, it didn't take long for her to build her confidence to not need to. I can't say if it has any effect on accuracy. I don't like wads and don't use them.

If your bullet casts over .224, using a .222 groove barrel, size it to .000 - .001 over groove size, before BSing and to start with BS your bullet to the chamber length.

The longer your chamber and larger your groove diameter, the lower the velocity will be.

I make my BSers out of 3/8 brass rod, turned to .220 - .222 for match type barrels and chambers. Sporting chambers are .775 long (longer if warn) and match chambers run .600 - .660 long so, it is helpful to be able to measure yours. I use gage pins, .001 over groove diameter to measure mine.

Frank

PS
I've been able to increase my B'eye charges to 1.8 gr, with a 48 gr bullet, when I had a Douglas barrel on my H&A 922.

As your charges go up, the extractor fit, will be important, to keep bulging under control.

You don't need much lube but, try full lube groove Vs rolled in lube.