I have a winchester model 100 in 308 cal. and i need some help. The trigger when pulled won't release the hammer. I have removed the complete trigger assembly to check for broken parts but have not taken the assembly or anything else apart. When I pull back on the lever or lock on the back side of the hammer just slightly and then pull the trigger the hammer will release.The rifle has had the firing pin replaced and nothing else. can anyone help. Thank you in advance for your time and knowledge.