513T & 521T Triggers
Not sure about the 510 being the same, but I think you are right, Clark.
I have a 521T (scaled down version of the 513T) that shoots very well, but the trigger is horrendous! I have not had the opportunity to measure pull weight, but I'm sure it's "off the scale." Seems it has gotten much heavier recently. I've cleaned it as best I can without disassembly, but no dice. Anyone know of what could go wrong to cause the trigger to become much, much heavier? I would be very happy just to get it down to 2 or even 3 pounds. How do I go about doing this? Does it take a special guru gunsmith to work on these old triggers? I found someone selling a "reduced power trigger spring kit." Know anything about these?