Daks,
My 7400 Carbine had an out of box trigger that reminded me of trying to drag a sled through sand. After about 200-300 shots it wore to the point of being usable. Not good, but usable. Does Timney or anyone make an aftermarket trigger for these rifles? I would suppose that judicious stoning and polishing may help, but these are assemblies unlike bolt triggers and would require someone familiar specifically with Rem 7400/7600 triggers to regulate them correctly. I would suggest trying to fire it several hundred times and then seeing of you can live with the trigger you get before having the trigger assembly worked. My thoughts, good luck.