I have heard of people shooting black powder loads through them to keep pressures down but realistically it isn't really a gun for shooting. The Italians in WWI as mentioned above only condoned shooting them if you really have no other option (i.e. you have a Austrian-Hungarian troop charging at you and this is the only rifle you have).

The history of them is pretty neat though. Originally they were the 1870/87 Vetterlis. In WWI the Italians found they didn't have enough rifles to go around for all there troops when they declared war on Austriaicon-Hungary (common problem for all nations involved, usually resulting in a foreign order for the Triple Entente (Franceicon, U.K., Russiaicon) and utilizing obsolete firearms in the case of the Central Powers (i.e. Germanyicon, Austria-Hungary and the Ottomans)). There solution was to take these obsolete 1870/87 Vetterlis and convert them to 6.5 Carcano. They did this by changing the magazine to one that would accept standard Carcano Mannlicher clips and by soldering in a barrel lining (I am not sure if they drilled it out first or just soldered it in the barrel). These rifles where then distributed to rear line troops (arty, etc.) who weren't expected to see close combat but still needed a rifle in case it happened and it apparently did happen on at least one case. With other Carcanos freed up they were then sent up to the front lines.

Issues I have heard of with these rifles are that the action wasn't designed for the load it was taking, and that if you shoot it there is a possibility that the barrel liner will shoot out as it was only soldered in place (this I have heard from people that have shot them). Overall they have a interesting history though I think the Italians might have been better off leaving them in the original caliber as to me that seems to be less sketchy (personally when I pull the trigger of my service rifle I don't want the risk of it blowing up in my face every time).