Until recently the Swiss government weapons assembly factory(W-FBern) assembled all the 7.5 military rifles(Model 1889 thru the Model1957) from numerous parts contractors. The only exception that I know of was the 1893 model by mannlicher(?spelling?)(hard to find and usually big bucks). The 11 types and later 7.5 types all used GP-11,with a cupro/nickel plating over a mild steel jacket. Actually there are a few exception to the shiny bullets the Swiss used but they are hard to find and rarely seen. All the earlier models used GP-90. They never chromed bores or used corrosive primers. W-FBern states that the correct diameterbulletis.3087". The Swiss solider almost never put a brush down their tubes but they did use basicly a bore snake and grease(Waffenfett and later Automatenfett). The Swiss cleaning technique involved a lot less work-no brushing- but grease, ungrease, shoot, grease, drink beer. I find it odd that one would find a 30 cal jag tight but an 8mm brush is OK. The tightness anyone feels would be that the bore is not .300" but more or less is .295-.297". The groove dia is .308. The 57 modeldoes use a rod instead of the pull rope but it also was basically greased. I use wipeout occasionally when I want a really clean barrel.Best