The Armsan and Hatsan semi automatic shotgun offerings whilst being reasonable value for money are well known for heavy trigger pulls and the issue with DiY fettling of the trigger is the things can be rendered unsafe very quickly. I remember someone pulling the trigger on a Hatsan and dumping the whole magazine, so he did it again just to confirm the issue. By this time he was starting to attract the attention of fellow club members, he was also now in unlawful possession of a Section 5 firearm and and all of the associated issues, so he rang me and asked me what he should do. Take the trigger box out and destroy it was the easy answer…
This Armsan A612 arrived the other day with a request to reduce the trigger weight. First job was confirm the existing pull which was a fraction over 3.5kgs or just under 8lbs in old money, time to find out what makes these things tick.
With the hammer spring removed the weight was checked again and was negligible so the trigger spring could remain a it was. There was room for some light stoning of the trigger however the real issue was that hammer spring rate which just happened to be an odd size (Of course!) So, a quick call to my spring people and a range of springs for testing were despatched.
Compression springs have many factors to consider, length, coil diameter, wire diameter, number of turns and weight. After this you can add material types as well…
So armed with a range of springs we sat down and worked our way down from the heaviest, looking for satisfactory primer strike, safe operation with all cartridges and absolute trigger safety. The final result was a trigger weight of 2.3kgs or just over 5lbs. Yes I could have gone lower and we actually had operation at just under 2kgs however the operation was scarily unsafe as the hammer dropped when slam checked, even when fitted with a heavier trigger spring.
So yes, you can reduce the trigger weight of your Hatsan or Armsan however dropping below 5lbs is going to get really marginal and you have to ask yourself what is more important, trigger weight or safety and you know the answer already.
Right, I am making shiny stuff for Accuracy Internationals today so best get them finished.