While I can't answer that directly, I can tell you that I replaced the trigger spring in my Rem 7400 and it made a world of difference. In fact, I was checking a couple of other rifles this evening after doing some work and checked the 7400 too. It's just a tad above 3 pounds now as a 5-pull average using my Lyman trigger pull gauge.
I just went and checked for you - this is the one I purchased:
Remington 7400 7600 760 740 4 6 REDUCED PULL! : Small Parts at GunBroker.com
At $8.25 + $3 shipping, you can't hardly lose. I also installed his kit in my Rem 11-87 shotgun. No, I'm not the seller, just a satisfied customer.