These rifles are an incredible amount of fun, easy to reload when you use 8 mm LaBelle brass to cut, size and fire form. Not difficult at all.
The conversion is very simple and there is a ton of information right here.
Vetterli Rifles - Swiss Rifles dot com
And for the Vetterli centerfire firing pin carrier, it's right here.
Vetterli firing pin carrier. | swissproductsusa
I just recently acquired one stamped M.81. No import stamp, all numbers matching and everything is original finish.
These were originally chambered in a 10.4 x 38mm rimfire (.41 Swiss). Since rimfire ammo of this caliber has not been made in many decades, a lot of owners have converted their rifle over to have the ability to shoot a .41 centerfire. The conversion process is a relatively simple one, and is reversible. However, if you convert the original bolt, it will always be apparent that a conversion was performed.
My rifle has not been converted, and I am personally debating whether or not to do the conversion. One option that I am seriously contemplating is modelling and machining a new bolt that is 'converted' for the .41 CF cartridge. This way I should be able to completely swap out the bolt so I can shoot the reloadable CF ammo, yet still retain the unaltered original bolt that would be able to be swapped back out should the need arise.
These rifles were originally designed in 1869 I believe. To put this into perspective, The US was just coming off of the civil war in 1865. The vast majority of those rifles were single shot muzzle loaders. This new Swiss design had a 12 round tubular magazine +1 in the chamber. A 13 shot repeating bolt action. Absolutely cutting edge technology at the time! Since this one is stamped M.81, it was manufactured in 1887, 88, or 89. Rifles manufactured form 1882 through 86 were still stamped as M.78, although they had the upgrades of the M81 design. These were designated as M78/81.
All in all, these are fascinating rifles that hold an important spot in firearm history.