Best left to a good gunsmith
See the link below for the Owners Manual. Read the section "Adjusting the Trigger."
Rossi IS the maker. Rossi is currently owned by Taurus.
There were a few that do not have a standard trigger, but use a THUMB trigger. Do a web IMAGE search for Winchester thumb trigger rifle, and you will find it.
Brownells and midway have them
no
If you are referring to a "SET Trigger" on a rifle. The Set Trigger releases all the normal mechanisms in the action but does not release the hammer on the rifle, but it sets up the firing trigger to act like a "Hair Trigger" just barley touch the firing trigger and the rifle goes off. It's used in hunting. It is common on black powder "Hawkins Rifles."
100 or so
Rossi
You will have to contact Rossi or find one of their catalogs
rifle basix makes the trigger of your dreams..
To adjust the trigger on a Savage Anschutz 141, first ensure the rifle is unloaded and safely pointed in a safe direction. Locate the trigger adjustment screws, typically found at the rear of the trigger assembly. Use a suitable screwdriver to turn the screws, adjusting the weight and creep of the trigger pull according to your preference. Always test the trigger after adjustments to ensure it functions safely and reliably.
10-100 usd