Yup, Carlos Diaopter is your man - especially if you live in Quebec. He can be found most days on
www.swissrifles.com. Here in UK and places east I've been shooting my K31 since 1989 and my 96/11 since 1995 - mostly with GP11 though.
Recently a HUGE price hike on the part of the principle importer - from £37 to £45 - has forced me into the full-time reloading of this easy to load-for round.
I can get PPU cases really easily, and can vouch for their toughness, although I also have three hundred Graf as well.
Loads for me, using the 150gr PPU bullet that sells for around £16/C here in yUK, have settled on 44.5gr of IMR4064 - oddly enough the exact duplicate as my best 155gr load in .308Win. Cases need to be full-length resized - no half measures, and NO crimping. Even this comparatively light load is very accurate out to the furthest I've ever shot with it - 600m - and makes even the best Lee-Enfield look like a yard-hose by comparison. The only possible rivals as issue military arms [although some might well argue] are the Finnish-built M39 - but NOT with issue ammunition, or the Carl Gustaf/Husqvarna with the 140gr bullet, again, not shooting military ammunition. But then again, I'm biased.
Accuracy in the 96/11 with open sights hovers around the inch - inch and half ten shots, for the K31, with an old El Paso Weaver x3 scope, around the inch, and with the Swiss Products Diopter sights, about the same.
If a reminder was needed, these are both strictly military arms that have been cared for using the correct cleaning regime with the correct cleaning materials - Swiss 'waffenfett' or the modern day equivalent [any GOOD quality yellow grease].
My 96/11 is dated 1914, and the K31 is from 1954.
Highly recommended - any of them.
tac
www.swissrifles.com