Here's a little something to help familiarize you with a bstaley O-ring buffer. I'll explain about the SSG in a follow up.
In its simplest form, it is just a stack of O-rings placed between the hammer and valve:
When you pull the trigger and the hammer flies forward and smacks the valve stem, it also hits the O-rings. The result is less lift and dwell which reduces the amount of air released by the valve, whereby giving you more shots at lower power.
Refer to this example:
See the blue curve at the top? The marking "3)70D" means qty 3 70 durometer O-rings and "0T" means zero turns on the hammer spring adjuster (minimum hammer spring tension). The velocity peaked at over 1000fps which is no good for pellets and the shot count was abysmal.
So I swapped out one of the 70 durometer O-rings for a harder 90 durometer, making the stack a little more firm overall, and also added a flat washer to make the stack a little taller. Then I plotted a couple more curves with differing amounts of hammer spring preload (3.5 turns and 1.5 turns as you see labeled).
The results were much closer to what I was looking for. I settled on the red curve in the middle. That took the power down from 18fpe to 14fpe and the number of useful shots (inside of a 4% extreme spread) more than doubled from 12 to 29. The total energy on a fill also increased by 66% (from 273fpe up to 454fpe).