Your rifle has a simple trigger, not a set trigger.
Set triggers almost always have two "triggers".
If I had your gun in front of me now, the first thing I would do would be to remove the lock.
With the lock removed, I would pull your trigger all the way to the rear, as far as it will go.
If the trigger moves freely and if the metal blade on the top of the trigger (inside the stock now) moves up to block off almost all of the hole in the wood where the sear arm (finger that sticks out away from the lock) goes I would proclaim the trigger OK.
If the trigger hangs up on the wood somewhere so its blade doesn't move up to cover the sear arm hole I would find out why it doesn't.
OK. Lets say the trigger is working fine.
The next thing I would do is to place the locks hammer in the "fired" position.
I would then try moving the sear arm with my finger.
There is a "sear spring" at the rear that keeps the sear against the tumbler but the sear should move without needing to put too much pressure on the sear arm.
If it didn't move freely against the spring pressure I would look for a screw that holds the bridle and serves as the pivot for the sear.
I would then loosen this screw a bit until the sear moves smoothly but freely against the spring pressure.
( The bridle is the thing that covers the sear and tumbler.)
Often, shipping oil/wax or an overly tightened sear pivot/bridle screw can make the sear almost impossible to move.
When this happens, the trigger pull becomes enormous.
If the trigger and the sear pivot are all right, the last thing I would look at is the sear spring.
This is a V shaped spring at the rear of the lock.
It pushes on the top of the sear to keep it against the tumbler.
For safety reasons (I guess), some companies make this sear spring about 5 times stronger than it needs to be.
It's only job is to make the sear snap into the full cock and half cock grooves on the tumbler, 100 percent of the time. It must be strong enough to do this job each and every time.
Any additional force made by the sear spring only increases the amount of pull that needs to be done to the trigger when the gun is fired.
This springs force can be lightened (reduced) by filing the outer (away from lock) surface in a tapered manner with the taper beginning at the bend in the V and ending at the tip of the spring that pushes on the top of the sear arm.
This makes the width of the spring narrowest at the tip.
If you choose to do this, file only in the direction of the spring blade (leaf), never across it.
ALL filing marks MUST be in the direction of the leaf or the modified spring will break.
Although this spring modification is a rather drastic move which should be saved only as a last resort I have modified locks this way to reduce the trigger pull from 10 pounds down to a very usable 3-4 pounds without a problem.