Maybe some of you gun guru's could explaine why the 7400 is so inaccurate and the 7600 a shooter.

I now have a 7400 in 270 win and my old 7600 30-06.I have not shot the 270 yet and was wondering if there was something I could do to make it more accurate.
How bad is bad,2-3 inch groups at 100 tards out of the 7400 or is it worse?
The desing is about the same,but ones a pump and one a auto.
Info please.
BBJ