................................
But back to the top: the Worst RIFLE. My vote goes to the Italian M91 Mannlichier-Carcano. Underpowered, used a poorly produced munition, inaccuarate at both short and long range due to a nonadjustable rear sight.
The gun was so unpopular that where ever it was sent, it was simply thrown away for something else. The Finns and later the Italians preferred the Russian Mosin-Nagant compared to this horrible device.
And strangely, this is the gun that was supposed to have shot JFK. A rather odd choice for sniper weapon.
Let me disagree with your vote. There is possibly some misinformation and a couple of mistakes in your assertions. First is that the rifle that shot JFK was a M91 when it was actually a M91/38. An evolution of the M91, but a WW2 weapon, so totally OT.
Second is the poorly produced ammunition. I have read lots of critics about the equipment and the weapons available to the Italian Army in WW1 in tenths of books, but I never came through bad comments about ammunition quality. WW1 vintage ammunitions (from a box found in the ice) has been fired recently by friends with full satisfaction. The myth about poor ammunition is something that grew post WW2, when an abundance of M91 (in all variants) became available internationally on the civilian markets. Very few knew outside Italy that the actual calibre of the 6,5 x 52 was 0,268 inches, while other ammunition in 6,5 mm such as the better famed Swedish 6,5 x 55 is 0.266 and others are 0.264. This caused the manufacture and use of totally wrong ammunition that lead to very poor performances. The original 6,5 x 52 has ballistic characteristics that are perfectly comparable with the much better famed 30-30 Winchester and the 6,5 x 55, using a less aggressive charge that leads to a longer lifetime for the gun with much less maintenance. All these are important aspects of a military weapon.
The real weakness of the 6,5 x 52 ammunition is it's stability at the impact. It was not uncommon for a bullet to come out of the hit body without leaving other damage but it's neat passage: too "humanitarian" for a military bullet!
The M91 was also rugged and possibly better than its opponents Mauser, Steyr and Mannlicher in terms of sensitivity to dirt, sand and mud.
Also, it used a symmetrical 6 cartridge loader (vs. 5 of its opponents) and was easier to reload than the Steyr whose loader could be inserted in one way only. Try yourself at night while wearing gloves!
Not to mention that field dismantling and mounting the M91 was foolproof.
The M91 was also extremely robust. The Germans captured hundreds of thousands of M91, M91/24 and M91/38 in 1943 and rebored many of those in 8mm Mauser, a much more powerful ammunition, to be distributed to second line troops. Not only it resisted well to the higher pressures but it was regarded as a reliable gun when Mausers were not available.
I would like to know where you found references to the Italians preferring the Moisin Nagant. I have never read anything about this in tenths of books (or again are you talking about WW2?). Could you please mention any reference?
If we talk about the worst gun of WW2, I may agree with you. The M91 (and subversions) was totally outdated, though still reliable within its limits.
At the time of the First World War, though not one of the best, the M91 was perfectly adequate, relatively inexpensive, easy to train illiterate peasants on, reliable and performed quite well.