[intercooler]

I have swapped recoil springs in a few of my Semi's (especially the 10's) but not on a set schedule or by a test method. This past week I let another shooter at my range shoot the Witness 10mm. The trigger has always been pretty light and I told him that. After he shot it he said Wow... seems light than any 1911. I thought it was close to my Dan Wesson but I shot yesterday and it is extremely light. I need a pull gauge but in anyone's experience does this mean time for a new spring there?

[1SOW]

A trigger spring can make a noticeable difference in SA pull weight.

If it's similar to the CZ spring, the "tang" can be slightly bent to give more or less spring weight. Go slow, it doesn't really take much. Needle nose pliers work.
I bought a "light weight" trigger spring for my CZ and it brought the weight down (1.8#) where I couldn't move and prestage the trigger without occassionaly dropping the hammer a little too soon.
I put the heavier spring back in and slightly bent the tang to lighten it just a little.

Homemade gage. Weigh the dowell, string and plastic cup. Add weights. I use 125gr bullets.:D I put the pistols in a padded vie and hang the contraption I made on the trigger where my finger presses. It's very consistant.
https://lh3.googleusercontent.com/-fLBoG3S2iAM/Tx-S8wIMKUI/AAAAAAAAAqk/g4tD4pLNHzI/s310/Trigger%2520Gage-1.jpg