Thanks
I would just like to thank everyone who have and are contributing to this thread.
I have tried the caustic soda and potassium nitrate method and it works very well on small items ( triggers , screws etc.) , the problem with larger pieces seems to be a matter of heat,
When you put a cylinder or barrel of a rifle in the solution its to cold to start with and quickly forms a layer of reddish brown which does not allow the rest of the chemical to penetrate properly.
I have some more potassium coming soon and I intend heating the larger items up to the required heat before immersing them in the solution. Will let you know the results in a couple of weeks hopefully.
ATB Graham
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