The current wisdom as to how much 1:1 diluted karo is necessary is as follows:
Karo (1:1 in vodka - drops):
PPM * ml / 2000
320 * 1000 / 2000 = 160 drops
Under the assumption that 20 drops is 1ml (damn close), you'd need 8ml of diluted karo.
So, you only shorted the karo by 140 DROPS! Oops.
It used to be a divisor of 16000 but there was a discussion a few months back and Kephra was involved and his recommendation was to lower the divisor to 2000.
So, with so little reducer, I'm sure there's a LOT of dissolved silver oxide and all that gunk is probably precipitated silver oxide. Sad to see you wasted that much silver but its all a learning experience.
Also, regarding gelatine for gel capping, the formula to calculate the correct amount (dry) is
Gelatine (mg):
PPM * ml / [160...80 ]
So in your case, we're talking 2000mg-4000mg (2-4 GRAMS)
I don't know how much gelatine is in 40 drops of solution, sorry