Same here. Bought one for the shotgun and one for one of my rifles to set up the scope roughly. Did not work at all.
The one for the shotgun can be used for some indoor training, but that's it.
My 692 has about 1500g 1st and 1600g 2nd Trigger.
This can be adjusted by working on the notches on both ways.
I would shoot a few thousand more and check again. Under 1400g could be a bit too light in my opinion.
I have used Loctite 648 which is the strongest adhesive out of this range. The Shear strength is up to 31N/mm² when used steel to steel
with clean surfaces and the right width of the gap inbetween. It works well on certain parts like bolts, screws or gearwheels dependig on the size
of the parts...
I think to re- solder the barrels with silver solder (needs quite high temperatures) the whole assembly has to be torn apart, grinded and cleaned completely and also being re-blued afterwards.
That may cause the high costs. Perhaps a failure in the solderig process has happendend or the...