The best trigger work comes from restoning the sear engagement but that's a bit beyond a lot of shooters. Try the spring trick (tho don't mess with that tiny spring at the rear end of the sear!) but don't be too suprised if you trigger ends up a bit mushy. The best solution is to save up for a "Rifle Basix" replacement trigger or have a good gunsmith take on reworking the sear.
My son's 17V had a horrible trigger until I redid it. It's tolerable now but in need of a slight readjustment of the sear engagement depth. Sure improved the grouping, though! ~Andrew