So, you can use the Secret Stash deed to whip out an Adamantine bullet.
You can use the Secret Stash deed to whip out a magic bullet (say, a Dry Load bullet, or a Tracer )
...But can you use Secret Stash to obtain an already-poisoned pitted bullet?
The cost of purchasing an already prepared poison compound for the purpose of treating pitted bullets is equal to the poison's base cost + 20 gp.
Add 5 GP, and that's your poisoned bullet...