Having trouble with my sons Marlin 925

[bernie]

My son and I were shooting his Marlin 925 Sunday and he shot a mag through it and then it was my turn. I fired a few rounds through it and noticed that the trigger pull was extremely heavy, much more than usual. I asked my son if he noticed it when he shot and he said that he had. I fired another round and then the real trouble started. When the bolt handle is picked up and the bolt unlocked, it cocks the rifle as normal. However, when the bolt handle is pushed back down and the bolt locked, it uncocks itself. What could be causing this and what do I need to look for?

 

[Birdhunter1]

The trigger spring is likely cocked sideways. I had it happen on mine but I had also changed the spring out to a lighter one so it was my fault not Marlin's. If you have not changed the spring take it to a gunsmith and have them look it over.