Developed in the late 1880s and adopted by the Italian Government, the 6.5×52mm Carcano was the official Military Battle-rifle chambering adopted by Italy in 1890. Neither the 6.5 Carcano cartridge nor the Model of 1891 Carcano battle-rifle were remarkable in any positive way. If examples of a smokeless-powder-era sub-par-chambering and battle-rifle exist, these are probably very high on that list. The one interesting feature of this combination is the gain-twist barrel used in the 1891 rifle. While gain-twist rifling has potential advantages, the poor design, quality, and performance of the rifle did nothing to garner favor for that rifling system. It is interesting to ponder what might have been if Mauser had incorporated the gain-twist rifling system used in the 6.5 Carcano into one of its well-engineered and well-made models. This could possibly have changed things. Perhaps shooters would know about gain-twist rifling because it might be used in commercial sporting arms today*. However, likely because the Carcano was so disliked for good reasons having nothing to do with the rifling system used, gain-twist rifling fell out of favor. Very little research has been done for sporting arms applications. This situation is likely to continue into the foreseeable future. If you have one of these rifles, Lee Precision offers the dies to help you work with it. Despite all my negative comments, when loaded with the right components, this can be an entirely effective deer round. And, I know from experience that playing with a cartridge and rifle that others have branded as less than the best, can be very fulfilling. It is all the more enjoyable when you figure out how to make the combination work better than anyone would ever expect. * In the gain-twist system, rifling rate starts very slow and progressively increases toward the muzzle until it approaches the desired twist-rate; then the increase in rate can slow until the desired final twist rate occurs; and then twist rate can remain fixed. Or the rate can simply reach the desired level precisely at the muzzle. Other designs are feasible — many artillery barrels have reversed-twist rifling to break loose a fixed nut that then spins freely to activate the fuze.