I had a strangly similar problem one time. A friend had a new Remington that he got in 300 win mag. He said the trigger was very hard to pull and, that the gun had a small delay when the trigger fell until the shot went off.

I took it to the range, and even after him telling me about it, I set up, looked thru the scope and tried squeezing the trigger. I squeezed that thing hard and when it finally clicked, I pulled my head up off the gun, THEN it went off. I wasn' t happy. I tore the gun apart and found that Remington had packed it with alot of gunky grease and this goober didn' t clean it all out. I cleaned it all out, including the firing pin hole in the front of the bolt, and it worked fine. Trigger was about 5 lbs after that.