High JWMcC,
That "extra" screw in the back face of your Carrier Block Arm is for positive slam down, as I explained in our previous post. Now that you have installed a stock side spring, it would be pretty "snappy" as you close the lever. The reason it's "snappy" is because the Lever face is in positive contact with the carrier arm all the way down, so both the side spring and the lever are powering the carrier arm down.
Here's my suggestion. Leave the screw alone in the carrier block arm. Call Longhunter Shooting supply and get a set of "SlixSprings" for your rifle and fit em. They will take a little fitting to clear the side plates properly. You'll be amazed at the effort that stock side spring takes.
Or, reduce the stock side spring you now have. It won't take much to make it "not a spring" so go slow and be careful.
You'll notice I did NOT suggest you remove the screw that gives you positive slam down.
Coffinmaker