The first box of 100 I shot through mine was Winchester and I really did not like them at all. I like CCI or for bulk use Federal with good results.
The charge handle is the handle used to cock the gun. Inside the action it rides on a guide rod. The factory rod is broached or peened or whatever it's called to capture the handle and its return spring on the rod. The Kidd kit I bought (among other items) has a fancy handle (pretty much for looks) plus a "special" guide rod (with a smooth end) and three springs (light, standard, heavy).
The cheapest and one of the most affective mods is to replace the rear group pin (bolt stop pin, solid metal) with a "bolt buffer" style. On mine, the bolt slamming the pin was louder than the ammo (with ear muffs) and seemed to shake the gun around affecting my novice markmanship. I used a Kidd unit there too because I liked its dual layer feature (smaller diameter metal rod inside "rubber type" outer layer) because it seems stronger and loger lasting the the plastic/delrin/acrylic styles sold on eBay.
Trigger work helps a lot too. That can range from small dollar tinkering to high dollar complete drop in units from the aftermarket. I merely installed a Wolff spring kit and shim kit from Michigan Center Outdoors ("lcshively" on eBay), polished the internal parts, installed 0.001" oversize pivot pins, installed a polished stainless magazine release and polished stainless automatic bolt release, then polsihed the trigger return spring plunger.
I may still replace the hammer/sear/disconnector with aftermarket parts later if I get the bug again. By feel I'd say the simple stuff I did took it from 8-9 lbs to probably 3-4 at the most.