Is the mainspring tensioning screw on the front of the grip frame functional? i.e. when you pull off the grip panels to look, does it contact the mainspring? If it is putting a lot of pressure onto the mainspring, unscrew it until there is no contact. That will lighten the mainspring tension as far as you can go without modifying or replacing the spring. My past experiences with three Pietta SS '58s was not good (cylinder/barrel alignment was off on all 3) but they were of 1990s manufacturing. I do not know about the latest, but from what I have heard is a much improved version from Pietta. Tuning my Uberti Remingtons was little more than backing out the tension screws until they no longer touched the mainspring and then turning them back in for about 1/2 turn of tension/contact with the mainspring. Voila! suddenly a nice, smooth considerably lighter hammer pull. On the 3 Piettas none of the tension screws contacted the mainspring so they were merely for appearance. I ended up having to thin the mainsprings in order to lessen the hammer pull to a reasonable level. The Piettas have a slightly heavier frame than the Ubertis and are much heavier than the even lighter Euroarms Remingtons I have. The grip shapes and sizes are different on all 3 makes of .44 Remingtons I have owned.
A second thing to look for is whether the tip of the mainspring is rubbing on the back of the hammer as it is cocked. One of my prior Remingtons rubbed the back of the hammer and when I shortened the spring just enough to relieve the contact the cocking effort was notably reduced.
I do not know if anyone makes a lighter Remington mainspring ready to install.