To answer your question, yes. The hammer spring is what will lessen the perceived trigger pull.
I fluffed and buffed mine, but was still not happy with the trigger. I initially went with the 9lb hammer spring and the stock trigger return spring. I had about a 1% failure to ignite my handloads. However, I think that it was due to the fact I was not fully seating the primers. I switched to a 10 lb hammer spring.....and I started manually seating my primers with a Lee Hand Priming Tool and I have had 100% ignition in all my handloads and commercially loaded ammo.