That's the ISU (I'm an old dog Bob with no interest in what the Frogs are calling things these days) Big Bore rules....they have a "Military Rifle" class at 1.6 kg, or 3.5 lbs, which is recapitulated in IIRC, NRA HP Rule 3.1.5 (Foreign Service Rifle). That's the part of "as issued" that obtains, and it's an issue of safety and uniformity. Oh...and for what it's worth, my 3 K-31's have NO problem passing a Vintage Rifle trigger weight....neither did the MANY other K-31's that shot in the Match Friday, including the Match Winner! Funny that only ONE rifle had a problem with the trigger weight when if, as you say, they ALL have under-weight triggers "as issued"? Curiouser and curiouser!