Find an Autogun preset with an envelope in the pitch keyboard mapping that matches that of the "gong" preset (i.e. it will have an offset).
Set seed 2 to ---- and the corresponding slider all the way to the top. Also set Mod Y, which controls Timbre morphing in these types of presets, to 100% (all the way to the top).
Make sure the fullness setting is toward the bottom (~-75% to -100%).
Go to options → Key → Link key to timbre seed 1 (optional if the sound is already random enough for you).
If the above doesn't appeal, try again with a different preset.
...and there you have some random-sounding bell-like sounds
Here are a couple of preset numbers to get started:
2557418890
6603
(Sorry there weren't more yet found. The good ones seem to be quite rare in Autogun...)
Hopefully these presets will be at least somewhat useful