There are MANY published methods for the disablement and destruction of small arms. Depending on the type of destruction desired, the methods used will vary. For example, do you desire to simply make the firearm non-functional, remove critical parts, cut into sections or convert to scrap metal/wood/plastic? Just about every government has published methods, depending on firearm type, to meet a specific goal.

As you are new to the question, I would suggest you start by reviewing some of the most general guidelines which rate the pros and cons of popular methods (*see attached document). Once you have specified the exact level of "destruction" as your final goal, then it will be clear which methods can best accomplish this that are within your means.

Many thanks Bill.